Typescript Performance: Going Beyond The Surface
summary
Upgrading TypeScript cuts a 35s compile to under 12s; a 14s project drops to 2s after replacing expensive styled-component inference with a simple typed function and named types. Use tsc --generateTrace plus the Chrome tracing view or typescript-analyze-trace to find the exact file and AST node causing slow checks. Large unions (example: 74,387 string literals) and heavy inference cause 112s files; extract or name complex types, add generics to skip inference, and enable incremental builds (tsbuildinfo).
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chapters (14)
- 0:00Introduction to TypeScript performance
- 2:05Why TypeScript performance matters
- 4:52Keeping TypeScript up to date
- 7:39How TypeScript compiler works
- 11:14Debugging slow builds
- 13:42Generating TypeScript traces
- 18:45Optimizing TypeScript config
- 19:08Simplifying complex types
- 20:37Refactoring for performance
- 22:03Skipping type inference
- 24:34Avoiding verbose types
- 25:37Using incremental builds
- 26:41Reporting performance issues
- 27:01Summary and final tips
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