I'm working on https://nuenki.app. It's a browser extension that translates sentences at your knowledge level into the language you're learning, so you learn through immersion as you go about your day.

I've been doing a lot of experiments evaluating LLM translation performance, and I used what I learnt (that LLMs make mistakes, but different LLMs make different mistakes, and they're better at critiquing translations than producing them) to make a hybrid translator (https://nuenki.app/translator) that beats everything else.

And I was invited to do a talk about that to a company, which was really cool! I'm 19, doing this in my gap year before uni.