Hands up if you've never actually seen FP out in the wild doing something.
Not saying it's not out there or useful - just saying that after 20 years I'm yet to come across it once.
Not saying it's not out there or useful - just saying that after 20 years I'm yet to come across it once.
Just because you don't see FP out in the wild being conspicuous, doesn't mean it's not there ;-)
- WhatsApp: famous for being written in Erlang, a functional programming language, and processing more messages a day than the entire global SMS network with a team of 50 backend engineers
- Discord: handling extreme amounts of chat/call traffic using Elixir, another functional programming language based on the same tech as Erlang
- Telephones: telephone switches from Ericsson (and in fact, internet switches from Cisco) use Erlang
- Docker: core virtualization component for macOS (hyperkit) written in OCaml
- Amazon EC2: another core virtualization component of all computes, parts of the Xen hypervisor, written in OCaml
Here's a list of companies using Haskell, with similar links to other functional languages: https://github.com/erkmos/haskell-companies. It includes names like Facebook, Tesla, Klarna, Target and Kaspersky.
Not to mention the FP paradigms used in Python, C++ and other languages. In fact, if you've never come across FP "in the wild doing something" then I suspect you're living very much off-grid.