what's your go-to for distributed rate limiting

Hey everyone, I've been trying to figure out the best way to do rate limiting across different services and instances. It's kind of hard to keep track of requests per user or API key when everything's spread out. I've seen stuff like Redis with Lua scripts, but I'm wondering what you all are doing. Are you coding your own solution, using a pre-built library, or maybe using features in your API gateway? What problems have you run into with whatever you've chosen?