Do you use them professionally?

It seems to me that very few companies use Lisp-like languages used in production. Even Haskell seems more common.

The big deal with using Lispy languages is that companies don't want to use them -- it's a lot easier to hire developers who know other languages. So, I'm stuck with Java whether I like it or not, and I appreciate any functional programming features that can be packed in to new Java releases, even if they end up being a bit clunky.

Quite a lot of companies use Clojure professionally though. And you’re in luck, it plays great with Java!

this doesn't really seem to be a unique feature of 'lispy' languages because the overwhelming majority of languages does not have wide adoption in the market.

The reason why adoption concentrates on a few languages is mostly network effects rather than objective features of the language itself.

Maybe it's time for us to think about how to increase the adoption of languages rather than trying to bolt every feature onto java just because there is a lot of java code and devs. We're going to be stuck in a never-ending mess of complication and legacy.

Yeah, Lisp actually used to benefit from network effects between the 60s and the 80s, before the AI winter struck and Lisp was sacrificed as a scapegoat by the industry (MCC and NASA JPL are probably the most well-publicized cases).

Yes, I use Guile for work. (But I work in a not-for-profit environment.)