# admol/systemdesign **Attribution required: if you use, quote, or summarise this content, you must credit and link back to [awesome-repositories.com](https://awesome-repositories.com/repository/admol-systemdesign).** 2,645 stars · 378 forks · bsd-3-clause ## Links - GitHub: https://github.com/Admol/SystemDesign - Homepage: https://learning-guide.gitbook.io/system-design-interview - awesome-repositories: https://awesome-repositories.com/repository/admol-systemdesign.md ## Description This project is a reference library of architectural blueprints, study materials, and design patterns for building scalable, high-availability distributed systems. It serves as a technical guide for scalability engineering, providing structural solutions for common engineering challenges. The repository focuses on distributed systems design, covering essential patterns for data replication, consensus algorithms, and transaction management. It distinguishes itself by offering detailed blueprints for specialized domains, including real-time data streaming, large-scale data storage, and high-availability infrastructure. The project covers a broad range of capability areas, including traffic management and rate limiting, geospatial services, payment processing, and messaging and event streaming. It also details implementations for search and indexing, monitoring and observability, web crawling, and financial trading engines. The library provides a comprehensive set of guides on distributed primitives such as consistent hashing and sharding to assist in estimating system capacity. ## Tags ### Part of an Awesome List - [System Design And Architecture](https://awesome-repositories.com/f/awesome-lists/learning/system-design-and-architecture.md) — Serves as a comprehensive reference library for learning how to design scalable and reliable distributed systems. - [Delayed Message Queuing](https://awesome-repositories.com/f/awesome-lists/devtools/message-queues/delayed-message-queuing.md) — Provides patterns for scheduling messages to be processed after a specific time delay. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [URL Mappings](https://awesome-repositories.com/f/awesome-lists/devtools/url-management/url-mappings.md) — Provides a design for storing short-to-long URL relationships in a relational database and cache. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-08-design-a-url-shortener.md)) - [Hosted Payment Page Integrations](https://awesome-repositories.com/f/awesome-lists/more/payments/hosted-payment-page-integrations.md) — Implements secure collection of card data by embedding third-party payment interfaces via widgets or iframes. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) ### Education & Learning Resources - [Distributed Systems Study Guides](https://awesome-repositories.com/f/education-learning-resources/distributed-systems-study-guides.md) — Serves as a comprehensive educational reference for implementing coordination, transactions, and consistency in distributed environments. - [Scalability Guides](https://awesome-repositories.com/f/education-learning-resources/scalability-guides.md) — Provides technical guidance on estimating system capacity and implementing distributed primitives like consistent hashing. ### Business & Productivity Software - [Social Connection Management](https://awesome-repositories.com/f/business-productivity-software/social-connection-management.md) — Uses graph database blueprints to manage and retrieve social friendship connections. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [Digital Wallet Management](https://awesome-repositories.com/f/business-productivity-software/digital-wallet-management.md) — Implements a persistent store for tracking merchant account balances and cumulative payment amounts. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Data Replay Systems](https://awesome-repositories.com/f/business-productivity-software/historical-data-analysis/data-replay-systems.md) — Provides systems for recalculating metrics or state by re-processing historical raw logs. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-06-ad-click-event-aggregation.md)) - [Hotel Inventory Management](https://awesome-repositories.com/f/business-productivity-software/hotel-inventory-management.md) — Details the design of inventory tables to track room availability and manage overbooking logic. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-07-hotel-reservation-system.md)) - [Inter-Account Fund Transfers](https://awesome-repositories.com/f/business-productivity-software/inter-account-fund-transfers.md) — Implements systems for executing currency movements between distinct financial accounts via idempotent APIs. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-12-digital-wallet.md)) - [Order Matching Engines](https://awesome-repositories.com/f/business-productivity-software/on-chain-order-books/order-matching-engines.md) — Implements FIFO bid-ask pairing logic based on price and time priority. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [Trading Order Monitors](https://awesome-repositories.com/f/business-productivity-software/order-lifecycle-management/trading-order-monitors.md) — Tracks financial order state transitions from submission to execution. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [Payment Coordination Frameworks](https://awesome-repositories.com/f/business-productivity-software/payment-coordination-frameworks.md) — Provides a framework to coordinate the lifecycle of payments, including risk checks and third-party execution. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Payment Disbursments](https://awesome-repositories.com/f/business-productivity-software/payment-disbursments.md) — Details the payout flow for distributing funds from corporate accounts to global sellers. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Payment Idempotency Controls](https://awesome-repositories.com/f/business-productivity-software/payment-idempotency-controls.md) — Provides mechanisms to prevent duplicate charges for a single payment operation using unique identifiers. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Payment Order Management](https://awesome-repositories.com/f/business-productivity-software/payment-order-management.md) — Implements backend systems for creating and tracking payment orders and handling fund transfers via providers. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Regulatory Risk Screeners](https://awesome-repositories.com/f/business-productivity-software/payment-processing-integrations/regulatory-risk-screeners.md) — Implements risk screening to check payment requests against financial regulations and block suspicious behavior. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Lifecycle Audit Trails](https://awesome-repositories.com/f/business-productivity-software/payment-records/lifecycle-audit-trails.md) — Implements append-only databases to record the immutable lifecycle of payment state transitions for auditing. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Balance Transfers](https://awesome-repositories.com/f/business-productivity-software/prepaid-credit-wallets/workspace-credit-balances/balance-transfers.md) — Provides capabilities for moving monetary credits between user accounts via a RESTful API. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-12-digital-wallet.md)) - [Message Filtering](https://awesome-repositories.com/f/business-productivity-software/tag-filtering-systems/message-filtering.md) — Implements mechanisms for selectively delivering messages from a stream based on tags or logic. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [In-Memory Counters](https://awesome-repositories.com/f/business-productivity-software/usage-tracking-systems/in-memory-counters.md) — Uses fast, time-expiring storage to maintain real-time request counters for users and IPs. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) ### Data & Databases - [Time Series Data Storage](https://awesome-repositories.com/f/data-databases/data-engineering-infrastructure/data-persistence-storage/data-storage/specialized-database-engines/time-series-data-storage.md) — Implements scalable storage solutions optimized for maintaining historical numerical performance data over time. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Append-Only Persistence](https://awesome-repositories.com/f/data-databases/data-engineering-infrastructure/data-persistence-storage/persistence-durability/append-only-persistence.md) — Implements append-only logging to disk to ensure high-performance sequential I/O and durability. - [Unique Identifier Generators](https://awesome-repositories.com/f/data-databases/data-management/unique-identifier-generators.md) — Describes generating globally unique identifiers for use in distributed systems. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-08-design-a-url-shortener.md)) - [Exactly-Once Processing Semantics](https://awesome-repositories.com/f/data-databases/data-processing-pipelines/data-processing-frameworks/exactly-once-processing-semantics.md) — Implements guarantees that each input record is processed exactly once despite system failures. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-06-ad-click-event-aggregation.md)) - [Data Replication](https://awesome-repositories.com/f/data-databases/data-replication.md) — Details architectural patterns for synchronizing data across distributed nodes to ensure high availability. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-06-design-a-key-value-store.md)) - [Database Sharding](https://awesome-repositories.com/f/data-databases/database-sharding.md) — Provides architectural patterns for partitioning large datasets across multiple database nodes. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-01-scale-from-zero-to-millions-of-users.md)) - [Distributed Atomic Transactions](https://awesome-repositories.com/f/data-databases/distributed-atomic-transactions.md) — Provides blueprints for coordination mechanisms that treat multi-node updates as a single atomic unit. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-12-digital-wallet.md)) - [Consensus Algorithms](https://awesome-repositories.com/f/data-databases/distributed-state-synchronizers/consensus-algorithms.md) — Implements distributed algorithms like Raft to ensure all nodes in a cluster agree on a sequence of operations. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-12-digital-wallet.md)) - [Large-Scale Dataset Management](https://awesome-repositories.com/f/data-databases/large-scale-dataset-management.md) — Covers the management of massive datasets using partitioning, consistent hashing, and distributed key-value stores. - [Single-Leader Replication](https://awesome-repositories.com/f/data-databases/primary-replica-replication/single-leader-replication.md) — Describes the leader-follower replication model to prevent data loss and ensure high availability. - [Real-Time Data Streaming](https://awesome-repositories.com/f/data-databases/real-time-data-streaming.md) — Designs low-latency pipelines for real-time event streaming of location and market data using pub-sub models. - [Index Sharding](https://awesome-repositories.com/f/data-databases/search-indexing-technologies/search-indexing/search-and-indexing/vector-search-indexes/index-sharding.md) — Details the horizontal partitioning of prefix-tree indexes across multiple servers for high-scale data handling. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-13-design-a-search-autocomplete-system.md)) - [Search Suggestions](https://awesome-repositories.com/f/data-databases/search-suggestions.md) — Provides a system for returning popular search terms that match a given prefix in real-time. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-13-design-a-search-autocomplete-system.md)) - [Spatial Indexing](https://awesome-repositories.com/f/data-databases/spatial-indexing.md) — Implements spatial indexing using geohashes to map coordinates to identifiers for efficient proximity searches. - [Key-Value](https://awesome-repositories.com/f/data-databases/storage-engines/key-value.md) — Provides blueprints for high-performance key-value storage systems supporting basic put and get operations. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-06-design-a-key-value-store.md)) - [Write-Ahead Logging](https://awesome-repositories.com/f/data-databases/write-ahead-logging.md) — Implements write-ahead logging to record changes to a persistent log before database application. - [Database Synchronization](https://awesome-repositories.com/f/data-databases/change-data-capture/database-synchronization.md) — Details real-time consistency maintenance between primary databases and caches. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-07-hotel-reservation-system.md)) - [Read Performance Optimizations](https://awesome-repositories.com/f/data-databases/concurrent-write-optimizations/data-write-throughput-optimizers/s3-throughput-optimizers/read-performance-optimizations.md) — Uses Bloom filters to optimize read paths by verifying key existence before performing disk lookups. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-06-design-a-key-value-store.md)) - [Consistency Tuning](https://awesome-repositories.com/f/data-databases/consistency-tuning.md) — Provides guides on tuning the trade-off between write acknowledgments, read consistency, and latency. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-06-design-a-key-value-store.md)) - [Message Batching](https://awesome-repositories.com/f/data-databases/data-buffering/message-batching.md) — Implements message batching to group multiple transmissions into single requests for higher throughput. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Time-Series Compression](https://awesome-repositories.com/f/data-databases/data-compression/time-series-compression.md) — Implements time-series data compression using double-delta encoding and historical data downsampling. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Caching](https://awesome-repositories.com/f/data-databases/data-engineering-infrastructure/caching-performance/caching.md) — Implements caching of expensive response results in memory to reduce database load and latency. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-01-scale-from-zero-to-millions-of-users.md)) - [Incremental Block Transfers](https://awesome-repositories.com/f/data-databases/data-integration-synchronization/replication-control-policy/secure-data-replication/incremental-block-transfers.md) — Implements incremental block transfers to reduce bandwidth by synchronizing only modified data blocks. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-15-design-google-drive.md)) - [Incremental Score Updaters](https://awesome-repositories.com/f/data-databases/data-modification-apis/incremental-syncing/incremental-score-updaters.md) — Implements mechanisms for adjusting numeric values in sorted collections in real time. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-10-real-time-gaming-leaderboard.md)) - [Automatic Rebalancing](https://awesome-repositories.com/f/data-databases/data-partitioning-strategies/automatic-rebalancing.md) — Provides architectural patterns for the automated redistribution of data partitions to maintain performance during cluster scaling. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Ledger Reconciliation](https://awesome-repositories.com/f/data-databases/data-reconciliation-engines/ledger-reconciliation.md) — Provides logic for comparing internal ledger data with external settlement files to resolve inconsistencies. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Leaderboard Sharding](https://awesome-repositories.com/f/data-databases/database-sharding/row-based-sharding/leaderboard-sharding.md) — Implements partitioning strategies specifically for scaling global leaderboards using range or hash-based distribution. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-10-real-time-gaming-leaderboard.md)) - [Idempotent Booking Prevention](https://awesome-repositories.com/f/data-databases/duplicate-detection-tools/atomic-duplicate-prevention/idempotent-booking-prevention.md) — Implements idempotency keys and database constraints to prevent duplicate bookings. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-07-hotel-reservation-system.md)) - [Notification Deduplication](https://awesome-repositories.com/f/data-databases/duplicate-detection-tools/atomic-duplicate-prevention/notification-deduplication.md) — Details a deduplication mechanism using unique event identifiers to prevent redundant notification delivery. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-10-design-a-notification-system.md)) - [Vector Clock Resolutions](https://awesome-repositories.com/f/data-databases/duplicate-detection-tools/write-conflict-resolution-policies/vector-clock-resolutions.md) — Implements conflict resolution using vector clocks to track causal ancestry and detect concurrent modifications. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-06-design-a-key-value-store.md)) - [Geospatial Calculations](https://awesome-repositories.com/f/data-databases/geospatial-calculations.md) — Implements mathematical functions for calculating distances and spatial relationships on geographic coordinates. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-02-nearby-friends.md)) - [Location Data Storage](https://awesome-repositories.com/f/data-databases/geospatial-data-services/geospatial-and-location-services/location-data-storage.md) — Details systems for collecting and managing historical position data from mobile devices. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-02-nearby-friends.md)) - [Double-Entry Transaction Journals](https://awesome-repositories.com/f/data-databases/historical-data-archiving/transaction-record-maintenance/double-entry-transaction-journals.md) — Provides a system for recording financial transactions as balanced debits and credits to ensure accuracy. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Messaging Throughput Scaling](https://awesome-repositories.com/f/data-databases/horizontal-database-scaling/resource-scaling-strategies/resource-aware-scaling-controllers/messaging-throughput-scaling.md) — Provides blueprints for dynamically scaling producer and consumer resources to handle message traffic spikes. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Inventory Caches](https://awesome-repositories.com/f/data-databases/in-memory-caches/inventory-caches.md) — Provides in-memory caches to accelerate room availability lookups and propagate database updates. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-07-hotel-reservation-system.md)) - [Inventory Tracking](https://awesome-repositories.com/f/data-databases/inventory-tracking.md) — Implements systems for tracking room availability across date ranges and validating occupancy against total capacity. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-07-hotel-reservation-system.md)) - [User Rank Retrievals](https://awesome-repositories.com/f/data-databases/inventory-tracking/ranked-leaderboards/user-rank-retrievals.md) — Details the system design for determining a specific user's exact numerical rank in a sorted score collection. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-10-real-time-gaming-leaderboard.md)) - [State Snapshots](https://awesome-repositories.com/f/data-databases/key-value-persistence-stores/snapshot-persistence/state-snapshots.md) — Accelerates state recovery by saving periodic immutable snapshots to avoid replaying full event histories. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-12-digital-wallet.md)) - [Redistribution Range Identification](https://awesome-repositories.com/f/data-databases/key-value-store-iterators/range-key-iterators/redistribution-range-identification.md) — Defines the process for identifying the specific range of keys that must move when a node joins or leaves. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-05-design-consistent-hashing.md)) - [Top User Retrievals](https://awesome-repositories.com/f/data-databases/leaderboard-data-structures/top-user-retrievals.md) — Provides architectural patterns for fetching the highest-scoring users for global leaderboards. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-10-real-time-gaming-leaderboard.md)) - [Message Routing](https://awesome-repositories.com/f/data-databases/message-brokers/message-routing.md) — Details implementations for distributing messages across servers using partition keys to ensure scalability and ordering. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Partition-Based Routing](https://awesome-repositories.com/f/data-databases/message-brokers/message-routing/partition-based-routing.md) — Describes distributing messages across servers using keys or random assignment to enable horizontal scaling. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Message Storage](https://awesome-repositories.com/f/data-databases/message-storage.md) — Provides database schemas and patterns for persisting massive volumes of chat communications. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) - [Notification Persistence](https://awesome-repositories.com/f/data-databases/notification-persistence.md) — Provides a design for persisting notification data and implementing retries to ensure delivery reliability. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-10-design-a-notification-system.md)) - [Optimistic Concurrency Control](https://awesome-repositories.com/f/data-databases/optimistic-concurrency-control.md) — Implements optimistic concurrency control using version numbers to prevent race conditions during bookings. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-07-hotel-reservation-system.md)) - [Watermarking for Late Events](https://awesome-repositories.com/f/data-databases/out-of-order-histogram-ingestion/watermarking-for-late-events.md) — Describes the use of watermarking to include late-arriving events in aggregation windows. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-06-ad-click-event-aggregation.md)) - [Proximity Business Search](https://awesome-repositories.com/f/data-databases/proximity-business-search.md) — Provides a blueprint for searching business entities within a specific geographic radius. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-01-proximity-service.md)) - [Query Caching Strategies](https://awesome-repositories.com/f/data-databases/query-caching-strategies.md) — Implements query latency reduction techniques using distributed memory caching and prefix length limits. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-13-design-a-search-autocomplete-system.md)) - [Metric Query Languages](https://awesome-repositories.com/f/data-databases/query-engines/metric-query-languages.md) — Provides patterns for using specialized query languages to analyze and aggregate time-series metric data for trends. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Read Replicas](https://awesome-repositories.com/f/data-databases/read-replicas.md) — Provides patterns for scaling read workloads by distributing query traffic across multiple database read replicas. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-01-proximity-service.md)) - [Block-Level Incremental Synchronization](https://awesome-repositories.com/f/data-databases/real-time-data-synchronization/bidirectional-file-synchronization/block-level-incremental-synchronization.md) — Implements incremental synchronization and compression to update only modified data blocks during file transfers. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-15-design-google-drive.md)) - [Real-Time Map Data Processors](https://awesome-repositories.com/f/data-databases/real-time-map-data-processors.md) — Describes systems that process real-time location streams to update map data and traffic conditions. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-03-google-maps.md)) - [Social Content Retrievers](https://awesome-repositories.com/f/data-databases/search-result-aggregators/social-media-search-aggregators/public-content-retrievers/social-content-retrievers.md) — Describes the process of retrieving post IDs from cache and hydrating them with full content objects. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [Message Order Enforcement](https://awesome-repositories.com/f/data-databases/task-queues/sequential-task-processing/message-order-enforcement.md) — Ensures deterministic order processing using strictly sequenced message numbers. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [Tiled Routing Graphs](https://awesome-repositories.com/f/data-databases/tiled-routing-graphs.md) — Provides a design for partitioning routing networks into tiles to optimize pathfinding. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-03-google-maps.md)) - [Time-Series Query Analytics](https://awesome-repositories.com/f/data-databases/time-series-data-modeling/time-series-statistical-profiling/time-series-aggregations/time-series-query-analytics.md) — Provides blueprints for analyzing timestamped metrics using frequency-domain transformations and time-dimension aggregations. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Event Sourcing Recoveries](https://awesome-repositories.com/f/data-databases/undo-logs/transaction-recovery-logs/log-state-recovery/event-sourcing-recoveries.md) — Details restoring system state by replaying an immutable log of events. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [URL Crawl Queues](https://awesome-repositories.com/f/data-databases/url-crawl-queues.md) — Provides designs for URL crawl queues that handle priority and politeness. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) - [HTML Parsing and Extraction](https://awesome-repositories.com/f/data-databases/url-crawl-queues/url-filtering-strategies/content-and-language-filtering/html-parsing-and-extraction.md) — Provides patterns for extracting links from HTML and filtering blacklisted sites for quality control. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) ### DevOps & Infrastructure - [High Availability Infrastructure](https://awesome-repositories.com/f/devops-infrastructure/high-availability-infrastructure.md) — Provides blueprints for designing resilient infrastructure using replication and failover to prevent data loss. - [High Availability Systems](https://awesome-repositories.com/f/devops-infrastructure/high-availability-systems.md) — Offers design patterns for maintaining continuous service uptime through load balancer failover and multi-region redundancy. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-15-design-google-drive.md)) - [Rate Limiting Algorithms](https://awesome-repositories.com/f/devops-infrastructure/rate-limiters/rate-limiting-algorithms.md) — Provides implementations of standard traffic regulation algorithms like Token Bucket and Sliding Window. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) - [Multi-Layered Caching](https://awesome-repositories.com/f/devops-infrastructure/caching-layers/multi-layered-caching.md) — Employs multi-layered caching and CDNs to store social graphs and content for low-latency feed retrieval. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [Messaging Server Clustering](https://awesome-repositories.com/f/devops-infrastructure/cluster-node-management/messaging-server-clustering.md) — Details the distribution of messaging channels across server clusters to ensure high availability and scalability. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-02-nearby-friends.md)) - [Latency Optimization](https://awesome-repositories.com/f/devops-infrastructure/latency-optimization.md) — Optimizes global latency by routing traffic to the nearest edge server for rate limit checks. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) - [Application-Level Rate Limits](https://awesome-repositories.com/f/devops-infrastructure/rate-limiters/application-level-rate-limits.md) — Implements patterns for restricting user post frequency to prevent spam in social systems. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [Distributed Rate Limiting](https://awesome-repositories.com/f/devops-infrastructure/rate-limiters/distributed-rate-limiting.md) — Synchronizes request limits across distributed instances using a shared data store. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) - [Hybrid Memory-Disk Storage](https://awesome-repositories.com/f/devops-infrastructure/scheduling/asynchronous-crawl-queues/durable-crawl-queues/hybrid-memory-disk-storage.md) — Details a hybrid memory-disk approach for storing and prioritizing pending URLs at scale. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) - [Asynchronous Service Decoupling](https://awesome-repositories.com/f/devops-infrastructure/worker-scaling/independent-model-component-scaling/asynchronous-service-decoupling.md) — Describes a producer-consumer model used to handle asynchronous communication and independent component scaling. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-01-scale-from-zero-to-millions-of-users.md)) ### Networking & Communication - [Social Post Distribution](https://awesome-repositories.com/f/networking-communication/communication-platforms-services/communication-platforms/social-media-integrations/social-post-distribution.md) — Details the flow of writing social posts to databases and caches before fanout distribution. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [Distributed ID Generators](https://awesome-repositories.com/f/networking-communication/distributed-systems-p2p/distributed-computing/distributed-id-generators.md) — Provides patterns for generating globally unique identifiers across distributed servers using timestamp partitioning. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-07-design-a-unique-id-generator-in-distributed-systems.md)) - [Load Balancers](https://awesome-repositories.com/f/networking-communication/load-balancers.md) — Provides blueprints for balancing network traffic across server pools to ensure high availability. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-01-scale-from-zero-to-millions-of-users.md)) - [URL Shorteners](https://awesome-repositories.com/f/networking-communication/url-shorteners.md) — Details the mapping of long URLs to shortened aliases using hashing and base-62 encoding. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-08-design-a-url-shortener.md)) - [Payment Webhooks](https://awesome-repositories.com/f/networking-communication/api-integration-frameworks/webhook-management/payment-webhooks.md) — Implements payment tracking using webhooks and polling to update internal order statuses for long-running requests. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Push Notification Providers](https://awesome-repositories.com/f/networking-communication/communication-platforms-services/messaging-notification-systems/messaging-services/notification-delivery-services/push-notification-providers.md) — Integrates with third-party push providers to alert offline users of new messages. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) - [Content Delivery Networks](https://awesome-repositories.com/f/networking-communication/content-delivery-networks.md) — Describes the use of Content Delivery Networks to ensure low-latency global access to heavy media files. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [WebSockets](https://awesome-repositories.com/f/networking-communication/distributed-systems-p2p/distributed-computing/communication-protocols/websocket-implementations/websockets.md) — Utilizes WebSockets to maintain persistent, bidirectional connections for low-latency data exchange between clients and servers. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) - [Snowflake ID Generators](https://awesome-repositories.com/f/networking-communication/distributed-systems-p2p/distributed-computing/distributed-id-generators/snowflake-id-generators.md) — Details the use of Snowflake-style ID generators to produce unique, time-ordered identifiers for distributed messaging. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) - [Node Failure Detection](https://awesome-repositories.com/f/networking-communication/distributed-systems-p2p/distributed-systems-coordination/distributed-systems-configuration/heartbeat-and-timeout-configurations/node-failure-detection.md) — Describes the use of gossip protocols and heartbeat counters to identify and handle node failures in a cluster. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-06-design-a-key-value-store.md)) - [Geographic Traffic Routing](https://awesome-repositories.com/f/networking-communication/geographic-traffic-routing.md) — Details the use of geoDNS to route traffic to the nearest data center based on geographic origin. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-01-scale-from-zero-to-millions-of-users.md)) - [Group Messaging Systems](https://awesome-repositories.com/f/networking-communication/group-messaging-systems.md) — Outlines the architecture for distributing messages to multiple recipients by replicating them into individual mailboxes. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) - [Consumer Group Coordinators](https://awesome-repositories.com/f/networking-communication/message-broker-consumers/consumer-group-coordinators.md) — Details systems for distributing stream messages across multiple workers to ensure reliable, load-balanced processing. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Message Brokers](https://awesome-repositories.com/f/networking-communication/message-brokers.md) — Explains the use of message brokers as an architectural pattern for asynchronous communication and decoupling. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Message Synchronization](https://awesome-repositories.com/f/networking-communication/message-synchronization.md) — Implements protocols for ensuring consistent message state across multiple client devices. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) - [Domain Name System Services](https://awesome-repositories.com/f/networking-communication/network-infrastructure-routing/network-infrastructure-configuration/network-and-server-infrastructure/domain-name-system-services.md) — Implements domain name resolution with caching to optimize latency for high-volume request environments. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) - [Request Routing](https://awesome-repositories.com/f/networking-communication/network-infrastructure-routing/network-routing-traffic-management/request-routing.md) — Provides patterns for directing incoming network requests to the appropriate internal services. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [Point-to-Point Messaging](https://awesome-repositories.com/f/networking-communication/point-to-point-messaging.md) — Describes the architectural pattern where each message in a queue is consumed by exactly one consumer. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Pub-Sub Messaging](https://awesome-repositories.com/f/networking-communication/pub-sub-messaging.md) — Covers the implementation of topic-based messaging systems where multiple consumers can receive the same message. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Scatter-Gather Patterns](https://awesome-repositories.com/f/networking-communication/scatter-gather-patterns.md) — Implements scatter-gather patterns to collect and aggregate results from multiple data shards in parallel. - [Optimal Server Routing](https://awesome-repositories.com/f/networking-communication/traffic-redirection-tools/optimal-server-routing.md) — Implements routing logic to match clients to servers based on proximity and current capacity. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) - [UDP Multicast Data Distribution](https://awesome-repositories.com/f/networking-communication/transport-layers/udp-transport-implementations/udp-multicast-data-distribution.md) — Details a reliable UDP multicast system for broadcasting real-time market updates to multiple subscribers simultaneously. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) ### Software Engineering & Architecture - [Architectural Design Patterns](https://awesome-repositories.com/f/software-engineering-architecture/architectural-design-patterns.md) — Offers a library of structural templates for organizing application logic, state, and component interactions. - [Consistent Hashing](https://awesome-repositories.com/f/software-engineering-architecture/distributed-systems/distributed-data-management/consistent-hashing.md) — Provides architectural patterns for mapping keys and servers to a circular hash space for scalable partitioning. - [Distributed Transaction Patterns](https://awesome-repositories.com/f/software-engineering-architecture/distributed-transaction-patterns.md) — Details architectural patterns like Sagas and atomic commits to maintain data integrity across service boundaries. - [Rate Limiting](https://awesome-repositories.com/f/software-engineering-architecture/request-throttling/rate-limiting.md) — Implements mechanisms for capping request frequency per client to maintain system stability. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) - [Social Feed Architectures](https://awesome-repositories.com/f/software-engineering-architecture/social-feed-architectures.md) — Provides architectural designs for reverse-chronological social feed aggregation. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [Social Graph Distribution Patterns](https://awesome-repositories.com/f/software-engineering-architecture/social-graph-distribution-patterns.md) — System pushing updates to followers using a hybrid model of pre-computed write-fanout and on-demand read-fanout. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [System Architecture Patterns](https://awesome-repositories.com/f/software-engineering-architecture/system-architecture-patterns.md) — Details design principles and patterns for building scalable and maintainable software systems. - [Trie Constructions](https://awesome-repositories.com/f/software-engineering-architecture/trie-constructions.md) — Outlines the construction of trie data structures for efficient search term storage and autocomplete retrieval. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-13-design-a-search-autocomplete-system.md)) - [Distributed Index Sharding](https://awesome-repositories.com/f/software-engineering-architecture/trie-data-structures/prefix-trie-filters/trie-caching/distributed-index-sharding.md) — Details the sharding of large prefix trees across multiple servers to balance load and manage memory constraints. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-13-design-a-search-autocomplete-system.md)) - [Crawl Prioritization Algorithms](https://awesome-repositories.com/f/software-engineering-architecture/crawl-prioritization-algorithms.md) — Implements algorithms like PageRank to prioritize high-value URLs during web crawling. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) - [Deterministic Event Sequencing](https://awesome-repositories.com/f/software-engineering-architecture/deterministic-event-sequencing.md) — Assigns monotonically increasing sequence numbers to orders and fills to ensure processing determinism. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [Virtual Node Mapping](https://awesome-repositories.com/f/software-engineering-architecture/distributed-systems/distributed-data-management/consistent-hashing/load-balancing-ring-hashing/virtual-node-mapping.md) — Implements virtual nodes on a hash ring to ensure uniform data and request distribution across physical servers. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-05-design-consistent-hashing.md)) - [Aggregation Verification](https://awesome-repositories.com/f/software-engineering-architecture/execution-control/declarative-reconciliation-engines/data-store-reconciliation/aggregation-verification.md) — Describes a verification system that compares real-time aggregated metrics against batch-processed raw logs for accuracy. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-06-ad-click-event-aggregation.md)) - [Failure Queues](https://awesome-repositories.com/f/software-engineering-architecture/failure-handling-policies/failure-artifact-management/failure-queues.md) — Provides a design for dedicated storage of failed tasks to enable manual inspection and retry. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Request-Level Idempotency](https://awesome-repositories.com/f/software-engineering-architecture/idempotency-mechanisms/operation-idempotency/request-level-idempotency.md) — Implements request-level idempotency using unique keys and database constraints to prevent duplicate processing. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Delivery Guarantees](https://awesome-repositories.com/f/software-engineering-architecture/performance-reliability/reliability-patterns/delivery-guarantees.md) — Details configurations and protocols that ensure messages are successfully received via acknowledgments and retry logic. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-04-distributed-message-queue.md)) - [Pub/Sub Event Distribution](https://awesome-repositories.com/f/software-engineering-architecture/pub-sub-event-distribution.md) — Illustrates broadcasting a single update, such as a location change, to multiple subscriber queues via a messaging bus. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-02-nearby-friends.md)) - [Dead Letter Queues](https://awesome-repositories.com/f/software-engineering-architecture/queue-implementations/dead-letter-queues.md) — Describes mechanisms for routing failed message delivery attempts to specialized handlers for recovery. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-11-payment-system.md)) - [Crawling Request Throttlers](https://awesome-repositories.com/f/software-engineering-architecture/request-throttling/crawling-request-throttlers.md) — Implements crawl-specific request throttling to prevent server overload via hostname mapping and delays. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) - [Rate Limit Signaling](https://awesome-repositories.com/f/software-engineering-architecture/request-throttling/rate-limit-signaling.md) — Provides mechanisms for returning status codes and headers to inform clients of remaining quotas. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) - [Latency Optimizations](https://awesome-repositories.com/f/software-engineering-architecture/request-throttling/rate-limiting/latency-optimizations.md) — Details the use of geographically distributed edge servers and eventual consistency to minimize rate-limiting latency. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) - [Rate Limit Rule Configuration](https://awesome-repositories.com/f/software-engineering-architecture/request-throttling/rate-limiting/rate-limit-rule-configuration.md) — Provides detailed patterns for configuring request thresholds and quotas using external configuration files. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) - [Sequential I/O Optimizations](https://awesome-repositories.com/f/software-engineering-architecture/sequential-i-o-optimizations.md) — Utilizes memory-mapped files and append-only logs to bypass network overhead and maximize disk throughput. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-12-digital-wallet.md)) - [Shared-Memory Architectures](https://awesome-repositories.com/f/software-engineering-architecture/shared-memory-architectures.md) — Implements end-to-end latency reduction by deploying components on a single server using shared memory. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [Stateless Architectures](https://awesome-repositories.com/f/software-engineering-architecture/stateless-architectures.md) — Details strategies for maintaining stateless web layers by moving session data to external persistent stores. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-01-scale-from-zero-to-millions-of-users.md)) - [Pre-Trade Risk Validators](https://awesome-repositories.com/f/software-engineering-architecture/validation-pipelines/pre-trade-risk-validators.md) — Provides pre-trade risk validation for trading volume and wallet balance checks before order execution. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [Web Content Deduplication](https://awesome-repositories.com/f/software-engineering-architecture/web-content-deduplication.md) — Implements web content deduplication using hashes and Bloom filters to prevent redundant page storage. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) ### Web Development - [URL Redirections](https://awesome-repositories.com/f/web-development/url-routing/redirection-rules/geographic-redirection/url-redirections.md) — Explains the mechanism for retrieving original URLs and returning HTTP redirects. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-08-design-a-url-shortener.md)) - [Web Crawling](https://awesome-repositories.com/f/web-development/web-automation-scraping/web-scraping-automation/web-crawling.md) — Provides a comprehensive system for discovering, navigating, and indexing web content using distributed servers. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) - [Service Decoupling Buffers](https://awesome-repositories.com/f/web-development/request-body-handling/request-body-buffers/asynchronous-request-buffering/service-decoupling-buffers.md) — Implements asynchronous buffering with message queues to decouple services and enable independent scaling. - [Distributed Crawling Infrastructures](https://awesome-repositories.com/f/web-development/web-automation-scraping/web-scraping-automation/web-crawling/distributed-crawling-infrastructures.md) — Provides architectural blueprints for scaling web crawling workloads across multiple servers using consistent hashing. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-09-design-a-web-crawler.md)) ### Artificial Intelligence & ML - [Command Query Responsibility Segregation](https://awesome-repositories.com/f/artificial-intelligence-ml/ai-powered-data-assistants/read-only-database-querying/read-write-node-separations/command-query-responsibility-segregation.md) — Provides blueprints for decoupling state updates from state queries to enable specialized read-only views. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-12-digital-wallet.md)) ### Content Management & Publishing - [Social Media Publishers](https://awesome-repositories.com/f/content-management-publishing/social-media-publishers.md) — Details the process of writing social media posts to a database and triggering distribution fanout. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) ### Development Tools & Productivity - [Merkle Tree Synchronizations](https://awesome-repositories.com/f/development-tools-productivity/browser-data-sync-tools/data-synchronization-tools/merkle-tree-synchronizations.md) — Utilizes Merkle trees to identify and synchronize only the differing portions of replicated datasets. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-06-design-a-key-value-store.md)) - [Presence Tracking](https://awesome-repositories.com/f/development-tools-productivity/change-tracking/real-time-synchronization/presence-tracking.md) — Tracks user availability via heartbeats and broadcasts status changes using a pub-sub model. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) - [Social Graph Data Querying](https://awesome-repositories.com/f/development-tools-productivity/integration-metadata-retrievers/media-metadata-retrievers/security-protected-media-retrievers/social-media-content-retrievers/social-graph-data-querying.md) — Provides methods for querying social graph structures and relationships using graph databases. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [Stream Buffering Pipelines](https://awesome-repositories.com/f/development-tools-productivity/memory-buffering-utilities/memory-buffering-pipelines/direct-buffer-processing/stream-buffering-pipelines.md) — Implements distributed queues to decouple metric collection from database ingestion, preventing data loss during downtime. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) ### Graphics & Multimedia - [Video Streaming](https://awesome-repositories.com/f/graphics-multimedia/streaming-distribution/streaming-broadcasting/media-streaming/video-streaming.md) — Provides blueprints for delivering video data incrementally using streaming protocols for immediate playback. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-14-design-youtube.md)) ### Scientific & Mathematical Computing - [Shortest Path Algorithms](https://awesome-repositories.com/f/scientific-mathematical-computing/numerical-mathematical-foundations/algorithms-and-complexity/algorithms/graph-processing/shortest-path-algorithms.md) — Explains algorithms for calculating the most efficient path between nodes in a routing graph. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-03-google-maps.md)) - [Route Calculations](https://awesome-repositories.com/f/scientific-mathematical-computing/route-calculations.md) — Details systems for computing optimal geographic paths using network graphs and cost models. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-03-google-maps.md)) - [Travel Time Estimation](https://awesome-repositories.com/f/scientific-mathematical-computing/travel-time-estimation.md) — Utilizes machine learning and traffic data to estimate travel durations between points on a road network. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-03-google-maps.md)) ### Security & Cryptography - [API Access Security](https://awesome-repositories.com/f/security-cryptography/api-access-security.md) — Provides architectural blueprints for securing API access using keys and rate limiting. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-11-design-a-news-feed-system.md)) - [DDoS Protections](https://awesome-repositories.com/f/security-cryptography/network-infrastructure-security/web-network-security/network-security/ddos-protections.md) — Offers design patterns for defending public interfaces against volumetric network attacks. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-13-stock-exchange.md)) - [Geo-Routing for Privacy](https://awesome-repositories.com/f/security-cryptography/user-privacy-protection/data-privacy-compliance/geo-routing-for-privacy.md) — Describes systems for routing network traffic to regional data centers to meet local data privacy laws. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-01-proximity-service.md)) ### System Administration & Monitoring - [Notification Frequency Control](https://awesome-repositories.com/f/system-administration-monitoring/alert-notification-systems/notification-frequency-control.md) — Provides a design for capping notification frequency on a per-user basis to prevent alert fatigue. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-10-design-a-notification-system.md)) - [Alerting Systems](https://awesome-repositories.com/f/system-administration-monitoring/alerting-and-incident-management/alerting-systems.md) — Describes systems that evaluate metric data against rules to route critical system alerts to administrators. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Notification Rate Limiting](https://awesome-repositories.com/f/system-administration-monitoring/alerting-and-incident-management/alerting-systems/alert-managers/notification-rate-limiting.md) — Implements volume controls combining rate limiting and user preferences to prevent notification flooding. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-10-design-a-notification-system.md)) - [Pull-Based Metric Scraping](https://awesome-repositories.com/f/system-administration-monitoring/logging-and-telemetry/metric-data-ingestion/pull-based-metric-scraping.md) — Outlines a pull-based mechanism for retrieving metrics from application endpoints at regular intervals. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Push-Based Metric Pipelines](https://awesome-repositories.com/f/system-administration-monitoring/logging/metrics-retrieval/metric-detail-retrieval/agent-health-metrics/push-based-metric-pipelines.md) — Details architectures where local agents actively push buffered telemetry data to a centralized collector. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Metric Collection](https://awesome-repositories.com/f/system-administration-monitoring/metric-collection.md) — Guides the implementation of push and pull models for gathering infrastructure health and performance metrics. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Metric Aggregators](https://awesome-repositories.com/f/system-administration-monitoring/monitoring-and-observability/observability-platforms/metric-performance-monitors/server-metrics/metric-aggregators.md) — Details patterns for summarizing telemetry data at the agent or query level to optimize storage. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [Queue Depth Monitoring](https://awesome-repositories.com/f/system-administration-monitoring/monitoring-and-observability/observability-platforms/operational-health-alerting/health-monitoring-endpoints/application-health-monitors/queue-depth-monitoring.md) — Provides logic for tracking queue depth to trigger automatic scaling of worker nodes based on pending task volume. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-10-design-a-notification-system.md)) - [Multi-Channel Notification Workflows](https://awesome-repositories.com/f/system-administration-monitoring/notification-channels/notification-channel-configuration/multi-channel-notification-workflows.md) — Implements a workflow to coordinate alerts across mobile push, SMS, and email channels via third-party integrations. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-10-design-a-notification-system.md)) - [System Health Monitoring](https://awesome-repositories.com/f/system-administration-monitoring/observability-instrumentation/system-health-monitoring.md) — Provides frameworks for collecting error logs and hardware metrics to identify production failures and operational insights. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-01-scale-from-zero-to-millions-of-users.md)) - [Rate Limit Monitoring Tools](https://awesome-repositories.com/f/system-administration-monitoring/rate-limit-monitoring-tools.md) — Describes systems for collecting analytics on dropped requests to tune rate-limiting rules. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-04-design-a-rate-limiter.md)) - [Reservation Systems](https://awesome-repositories.com/f/system-administration-monitoring/resource-scheduling/reservation-systems.md) — Outlines the architecture for creating, retrieving, and cancelling hotel room bookings. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-07-hotel-reservation-system.md)) - [Concurrency Control Mechanisms](https://awesome-repositories.com/f/system-administration-monitoring/resource-scheduling/reservation-systems/concurrency-control-mechanisms.md) — Implements locking mechanisms and database constraints to prevent race conditions during high-demand bookings. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-07-hotel-reservation-system.md)) - [Monitoring Data Visualization](https://awesome-repositories.com/f/system-administration-monitoring/system-metrics/visual-graphing/monitoring-data-visualization.md) — Details the visualization of time-series data and alert statuses using dashboards, graphs, and network topology maps. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-05-metrics-monitoring-and-alerting-system.md)) - [User Presence Monitoring](https://awesome-repositories.com/f/system-administration-monitoring/user-presence-monitoring.md) — Details a system for tracking real-time user connectivity and online status using heartbeats and key-value stores. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-12-design-a-chat-system.md)) ### User Interface & Experience - [Route Ranking](https://awesome-repositories.com/f/user-interface-experience/navigation-routing/route-ranking.md) — Implements logic for filtering and sorting navigation path options based on user preferences like avoiding tolls. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-er-juan/chapter-03-google-maps.md)) - [User Notification Preference Centers](https://awesome-repositories.com/f/user-interface-experience/user-notification-preference-centers.md) — Implements logic for validating user opt-in settings and channel preferences before dispatching notifications. ([source](https://learning-guide.gitbook.io/system-design-interview/xi-tong-she-ji-mian-shi-nei-mu-zhi-nan-di-yi-juan/chapter-10-design-a-notification-system.md))