I’m happily using fiber in go. To be precise, I do definitions in protobuf, use grpc-gateway to auto build the api server, and wrap it with fiber for better middlewares.

I get swagger ui and “all the clients” for free, thanks to protobuf.

With this said, imo it all depends on how much web dev you have to do. If it’s really just an api, that’s my current stack. If there’s a lot of frontend, I’d prob lean for a similar solution built with a js/ts backend like nextjs or plain express.