Typescript Performance

TypeScript Performance

Use When

• Profiling TypeScript applications for CPU, memory, or bundle size issues.
• Analyzing type-checking and build time performance.
• Optimizing bundle size and startup time.

Profiling Tools

1. Node.js profiling

• CPU: node --prof app.js then node --prof-process to analyze.
• Memory: Use Chrome DevTools heap snapshots or --inspect.
• Flame graphs: Use 0x package or native --prof + tools.

1. Build and bundle analysis

• Type-checking: tsc --diagnostics or tsc --listFiles to trace performance.
• Bundle: Use webpack-bundle-analyzer, rollup-plugin-visualizer, or esbuild --metafile.
• Sourcemap impact: Check .map file sizes; consider source-map-loader overhead.

1. Type-checking overhead

• Profile tsc compilation: time tsc --noEmit.
• Check for expensive patterns: deeply nested generics, complex type unions, circular type references.

Checklist

1. Type-checking and build performance

• Are expensive type operations (deep generics, complex unions) unavoidable, or can they be simplified?
• Is type-checking parallelizable? Use project references for large monorepos.
• Are sourcemaps necessary for production? Remove them for speed/size.

1. Runtime performance

• Identify hot paths with CPU profiling; focus optimization there.
• Check for unnecessary object allocations in loops.
• Verify async operations are not blocking the event loop.

1. Bundle and startup

• Analyze bundle composition: what is the largest and most-imported module?
• Check for dead code; use tree-shaking rules in tsconfig and bundler.
• Consider code splitting and lazy loading for large features.

1. Memory efficiency

• Look for large object retention or circular references in heap dumps.
• Check for memory leaks from event listeners or timers not cleaned up.

Output Requirements

For each finding provide:

• Measurement (current baseline, profiling evidence).
• Root cause and impact.
• Optimization strategy with expected improvement.
• Effort and risk assessment.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: caraya
• Source: caraya/agent-skills
• License: MIT

Install and usage instructions live in the source repository linked above.