A single Node.js process uses one CPU core. Scaling to the other cores — and to the many machines behind a load balancer — requires a specific set of patterns: streams with backpressure, typed errors with circuit breakers, cluster and worker threads, connection pools, cache-aside, sagas, and end-to-end observability.This book teaches those patterns from the event loop up. You will start with what blocks the loop and why it matters. You will build streaming pipelines that process data larger than memory. You will handle errors as operational versus programmer failures. You will cluster across cores and offload CPU-bound work to worker threads. You will split services safely and connect them with queues, idempotency keys, and circuit breakers. Every chapter ships with runnable code, benchmarks, and the failure modes that appear only under production load.Written for backend engineers, Node.js developers, and architects who need systems that survive traffic.
