There's two things that really stand out for me on TypeScript. There are other positive attributes, but these are the two things I liked. The first is that it

There's two things that really stand out for me on TypeScript. There are other positive attributes, but these are the two things I liked. The first is that it made some specific workflows a lot easier. In particular, I'm working on some pre-alpha libraries where there's movement on how the API interface is defined. TypeScript made that transition a lot easier. Yes, my testing would have eventually caught all the method arity mismatches, but TypeScript made this happen about an order of magnitude faster. The second is how unobtrusive the types actually are. I did a fair bit of J2EE programming in the 00s, and types and interfaces can be really annoying. With typescript, interfaces are assertions about the shape of an object, rather than things themselves. That means, if you defined an interface as HasFirstName: { firstName: string } and function greet(person: HasFirstName), you don't actually have to put HasFirstName everywhere in the code that uses that function. You're not required to set up inheritance or anything. You just have to make sure that all arguments to greet have a firstName property. That's it. So I can say: const dude = { firstName: 'the' }; greet(dude) just fine. But if I try to greet(potato), it'll error. Lexical typing this way gives you a lot of power while still staying out of your way in a language like javascript where it's super common to create consts as bags of properties without worrying about what particular interface they're instantiating. I really like that, as it is precisely the overbearing types of Java that annoy me.