What problem does it solve? Setting up VS Code debugging for Node.js, Fastify, and Next.js projects involves non-obvious configuration details — source map resolution, inspector flags, attach ports, and profiling workflows — that frequently cause breakpoints to miss or profiles to be unreadable. This Skill provides complete, working launch.json configurations and step-by-step profiling workflows so you can diagnose slow endpoints, memory leaks, and test failures without trial and error. ## Core Features & Use Cases - Ready-to-use launch.json configurations: Attach mode, Fastify launch, CPU profiling, heap snapshots, Next.js server and client debugging, and Jest test debugging. - CPU profiling workflow: Step-by-step flame chart capture and interpretation, with a table of common bottlenecks (async waterfalls, blocking JSON, N+1 queries) and their fixes. - Memory leak detection: Heap snapshot comparison workflow with common leak patterns (EventEmitter listeners, unbounded caches, timer closures) and fixes. - Source map troubleshooting: Concrete launch.json and tsconfig.json settings to fix breakpoints not hitting in TypeScript projects. - Use Case: Your Fastify endpoint is slow in development. Use this Skill to generate the CPU profile launch config, capture a flame chart while sending test requests, identify an async waterfall in the hot path, and fix it with parallelized awaits. ## Quick Start Ask the assistant to set up VS Code debugging and CPU profiling for your Fastify or Next.js project and generate the launch.json configuration.
