And here's a list of projects on GitHub tagged with the topic "TypeScript", sorted by most stars. Many build tools I see on the first page, starting with the TypeScript compiler itself - which is an impressive and interesting codebase, but it may not be so suitable for study purpose.
Awesome TypeScript - https://github.com/dzharii/awesome-typescript
And here's a list of projects on GitHub tagged with the topic "TypeScript", sorted by most stars. Many build tools I see on the first page, starting with the TypeScript compiler itself - which is an impressive and interesting codebase, but it may not be so suitable for study purpose.
https://github.com/topics/typescript
You might enjoy learning from some books too.
The TypeScript Handbook - https://www.typescriptlang.org/docs/handbook/intro.html
TypeScript Deep Dive - https://basarat.gitbook.io/typescript/