OCaml has a pretty decent language server [1]. You can pair it with the excellent OCaml vscode plugin [2], or any other LSP plugin for the editor of your choice.
The VSCode plugin and language server are really good. They're not quite on par with rust-analyzer, but I very rarely have issues with them, especially when using esy as the package manager (because you can easily set the version of the language server and be sure that everyone on the team is on the same version).
[1] https://github.com/ocaml/ocaml-lsp/
[2] https://marketplace.visualstudio.com/items?itemName=ocamllab...