I returned from paternity leave to find the team had shifted from Unity’s C# codebase to TypeScript. Having just finished the C# course on Codecademy in December, I was glad to find they had a TypeScript course too.
Prior experience with Python’s mypy type-checker made TypeScript’s type system feel familiar — the conceptual leap was smaller than expected. I also found useful parallels in package management and scripting approaches between languages.
The broader lesson from three years of picking up new languages (Standard ML, Racket, C#, TypeScript): it’s really just a matter of getting used to how a language reads and writes. Once you’re past that, the fundamentals you’ve already learned transfer.
I was contributing to the new codebase before the course was finished, with support from colleagues.