FP in a commercial setting is not that big in Belgium, but definitely not non-existing.
Specifically, in the Ghent area, I am aware of 4 companies that run on FP in production:
- Western Digital (through its Amplidata acquisition) has major components in Ocaml (disclaimer, I work for them)
- PieSync, has a Haskell component in production
- Waylay.io, seems to be using Scala
- Openvstorage, Ocaml users
There are probably more, so if anyone else could chime in, that would be appreciated.