This is incredible. If I knew I'd be working on things like this (as opposed to optimizing ad revenue or "user engagement" by A/B testing button copy), I'd possibly consider working at Meta.
At Meta you choose what team you want to work on during a 3 month “bootcamp” period, very different from Google, Amazon, etc. There’s enough teams solving hard distributed system problems that you’re guaranteed to never need to think about button copy
You can also be directly hired onto a team, skipping bootcamp (some roles).