Everyone's heard by now that TypeScript "went native." And I keep seeing the same wrong conclusion drawn from it: that TypeScript now somehow runs without being compiled, that the build step is gone, that your .ts files execute directly.
None of that happened. Your browser still can't run TypeScript. Node still can't type-check it. The thing that went native isn't your code. It's the compiler.
And honestly, that's the better story.
What "Native" Actually Means
For its entire life the TypeScript compiler has been written in TypeScript. tsc, the thing you run in CI and tsserver the thing feeding your editor its red squiggles were JavaScript programs executing on Node.js. Every type-check of your million-line codebase was itself a JavaScript program churning through a pointer-heavy graph of type objects, single-threaded with JIT warmup and garbage-collector pressure along for the ride.
