Which is good.
It handled everything fairly well, for a short-lived (month or two), API server that received several hundred thousand requests a second. (A stand-in server to handle some updating for some hardware in the field. Our normal server failed catastrophically, and took out the entire rack, which included the backup... So we needed something up quick, whilst we rebuilt the backup and redeployed the front-facing servers.)
It was fast to work with, but that's sort of a given with any Lisp, even though we had some ties between web, typed, and lazy Racket.
The documentation wasn't awesome. There's enough to get you started, but at the time, there wasn't a lot more.
But, Racket is fairly predictable in how functions are exposed, and how they should work. (As well as having a REPL to rapidly prototype).