TypeScript 7 moves its compiler to Go: what changes for those of us who write code?

On large projects, waiting for type checking also costs time: it interrupts work and delays the validation of changes.

TypeScript 7.0 introduces a native compiler written in Go. It combines native execution and shared-memory parallelism to make better use of the hardware.

Microsoft reports typical speedups of 8 to 12 times on full builds. That’s a reference point for the compiler’s performance; the result on each project still needs to be measured. See the source.

The improvement can shorten the time between making a change and getting the type errors back. For a team, that feedback loop deserves attention.

But before migrating, I’d review a dependency that often goes unnoticed: the tools that use the TypeScript API.

Version 7.0 shipped without a stable programmatic API. Microsoft documents how to keep TypeScript 6 alongside the native compiler for tools that still need it, such as typescript-eslint.

I’d evaluate a migration in three steps:

• Compare type checking on the same code, configuration, and machine.
• Measure clean builds and cached runs separately.
• Check linting, the editor, and the CI pipeline.

That way we can tell how much our workflow improves and what adjustments the project’s ecosystem requires.

How long does type checking currently take in your project?