nodejs-development_skill

Overview

This skill provides practical, hands-on guidance for building modern Node.js applications. It covers the event loop, async patterns (callbacks, promises, async/await), streams, file system operations, HTTP servers, process management, and production best practices. Use it to write efficient, non-blocking servers and resilient background workers. The content focuses on actionable patterns and common pitfalls to avoid in real projects.

How this skill works

The skill explains core internals like the event loop phases and scheduling priorities (process.nextTick, microtasks, timers, check). It demonstrates async patterns and migration paths from callbacks to promises and async/await, plus utilities like util.promisify. It shows stream types, pipeline and backpressure handling, efficient file I/O, and patterns for worker threads, clustering, and process management. Examples include code snippets for reading/writing files, streaming pipelines, creating HTTP servers, and offloading CPU-bound work.

When to use it

• Building REST APIs, microservices, or GraphQL servers
• Implementing real-time features with WebSockets or Server-Sent Events
• Processing large files or streaming data with backpressure
• Writing CLI tools, automation scripts, or serverless functions
• Creating background job processors, worker pools, or scheduled tasks

Best practices

• Never block the event loop—offload CPU work to worker threads or child processes
• Prefer streams and pipeline for large data to reduce memory usage and handle backpressure
• Use async/await with structured error handling; use Promise.allSettled for independent parallel tasks
• Favor ESM for new projects; keep clear module boundaries and small single-responsibility files
• Use atomic file writes and robust filesystem checks (fs.promises + rename) in production
• Gracefully handle process signals, implement health checks, and use clustering for multi-core scaling

Example use cases

• High-throughput JSON REST API with streaming request/response handling
• CLI tool that processes large logs using Transform streams and pipeline
• Worker service that offloads heavy computations to worker threads
• File ingestion pipeline that compresses and uploads large files using stream/promises
• Microservice gateway that proxies requests and applies middleware for validation and rate limiting