I used TypeScript one year, and found that for this kind of problem there are basically no benefits over JavaScript, and because of that it's also not a great way of learning TypeScript.

For this kind of thing JS is actually good as you can do messy things fast without worrying. Like a few of the problems this year benefitted from being able to mutate structures while iterating over them; I would never do that in production code but for fast hacking/golfing it is an excellent footgun. I did a lot last year in Rust and k (the polar opposites?); Rust was really annoying for this kind of thing.

Yep js is pretty great but I don't think it can best python for this kinda stuff, python has so many helper functions around these kind of problems where you'd have to constantly reinvent the wheel with js. And I shared the same opinion as about the this type of code. Not a fan of python in prod, but typescript all the way

Excel+Sheets taken together even >1.2% :-)

And 3 respondents answered they use their own custom language :O

Yes, this year I redid all my solutions in our own language (been working on it for 2 years with a friend) after submitting; to test how will it works for these cases. I must say, next year we'll definitely do it fully in our language.

That's absolutely amazing!!