async-background

https://github.com/roman-haidarov/async-background

A production-grade lightweight background job scheduler built on the Fiber::Scheduler interface itself, not on any one implementation: it runs under Async/Falcon, Itsi, or anything else that installs a scheduler. Single event loop with min-heap timer, skip-overlapping execution, jitter, monotonic clock intervals, semaphore concurrency control, and deterministic worker sharding.