I develop in OCaml from time to time, and it's pretty practical. Separate compilation, makes small-ish binaries that most people wouldn't know weren't written in C/C++, fast, garbage collection reduces mental burden, easily call out to C if you need to. We steer clear of the more complex language features like functors because they confuse most programmers.

Here's an example of one very widely used production application: https://github.com/libguestfs/virt-v2v/tree/master/v2v

It fits a similar niche to Golang or C++, but unlike those it's an enjoyable language to program in.