What’s surprised me in the last few months is that agents are great at producing OCaml 5+ and OxCaml code, not much of which is out there in the training data. OxCaml’s strong types and modes seem to serve as great testable oracles to guide the agents.
I taught a course on concurrent programming based on OCaml 5 and OxCaml where almost all of the code in the teaching materials were vibe coded. I reviewed all of the code (because I was teaching it to a class of 50+ students) and frankly the agent writes better O(x)Caml (mostly) than me.
I must confess to also using agents to do most of my OxCaml annotations: https://github.com/avsm/ocaml-claude-marketplace/tree/main/p...
There's not that much downside since the annotations only change the performance characteristics of the program, and the static type system rejects inconsistent annotations.