Async Concurrency Patterns

Promises, async/await, Promise.all/allSettled, worker_threads for CPU-bound work.

Why we need this / what value this brings

Node is single-threaded for JS execution — knowing when to reach for worker_threads vs just awaiting I/O matters.

When to use this

Any I/O-bound backend code (default: async/await) vs genuinely CPU-bound work (worker_threads).

How to use or implement this

Promise.allSettled over Promise.all when partial failure is acceptable; avoid blocking the event loop with sync CPU work.

Research questions

• (add as research surfaces open questions)

---

Empty folder — drop notes, links, and findings here as you research.