Javascript is a dogshit language that everyone is stuck with. The best that we can hope for is the likes of typescript take the edge off of it. Even though it’s like smearing marzipan over a turd. At least it’s ok if you don’t take a deep bite.

What I’d wonder is why it’s such massive expensive for Duolingo to hire 2 or 3 people to cover a language anyway. Presumably most of the work is contractual - hire somebody competent to produce a course, get somebody to say the lines, refine the course based on feed back and that’s mostly it.