BullMQ

1. Introduction

   What BullMQ is: Redis-based queue library and its core architecture.

2. Queues

   Creating queues, adding jobs, bulk adds and queue options.

3. Workers

   Processing jobs, concurrency, graceful shutdown, stalled jobs and sandboxed processors.

4. Jobs

   Job lifecycle and states, delayed, prioritized, LIFO, repeatable and deduplicated jobs.

5. Job Schedulers

   Repeatable jobs with cron and every-N-ms schedulers.

6. Retrying Failing Jobs

   Attempts, backoff strategies, unrecoverable errors and manual retries.

7. Flows

   Parent-child job dependencies and building job trees.

8. Rate Limiting

   Global and manual rate limiting of workers and queues.

9. Events

   Worker, queue and QueueEvents event streams for monitoring job progress.

10. Connections

    Redis connection configuration, reuse and ioredis options.

11. Parallelism and Concurrency

    Scaling workers by concurrency, multiple processes and sandboxed processors.

12. Going to Production

    Persistence, maxmemory policy, graceful shutdown, auto-removal and security for production.

13. Metrics

    Collecting queue metrics and Prometheus-style monitoring.

Each section links to the official page. Titles and summaries by Extra Credit; the docs belong to their authors.