Sidekiq is a Ruby background processing framework and asynchronous task runner. It functions as a Redis-backed background job processor that offloads heavy or time-consuming work from web requests to separate worker processes to ensure the main application remains responsive.
The system operates as a Redis task queue, storing pending jobs in Redis to be processed concurrently by multiple threads. It provides a framework for distributed task queueing and asynchronous job scheduling to coordinate work across multiple server instances.
The project covers Ruby application scaling by executing background jobs on separate threads, allowing the application to handle multiple concurrent operations without blocking the main process.