worker-pool: A Zero-Dependency Worker Thread Pool for Node.js

Node.js is single-threaded. For I/O-bound workloads, that's a superpower — the event loop handles thousands of concurrent connections without thread-switching overhead. But for CPU-bound work — image processing, cryptography, PDF generation, data transformation — a single thread is a hard ceiling. Everything queues behind the slow computation, and latency spikes. The standard solution is worker threads. The standard problem is that managing a pool of them is 200 lines of boilerplate you don't want to write on every project. worker-pool solves this. It's a zero-dependency worker thread pool with a single clean API: give it a worker script, tell it how many threads you want, and call pool.run(data) . The Problem: Raw Worker Threads Are Manual Here's what un-pooled worker threads look like in practice: // Without a pool — you write this for every request app . post ( ' /process ' , async ( req , res ) => { const worker = new Worker ( ' ./heavy-worker.js ' ); worker . on ( ' message ' , re