This is really cool! Had not heard about them. Thanks!

Nice, so looks like low hundreds of developers may be possible given the right environment.

That said, I don't feel it disproves my impression. If the company is 37 years old, still privately held and still has less than a hundred developers then it is clearly not a company looking to grow fast above all else. So feels like a nurturing environment for Lisp.

They may also not need to. They may have enough people working in a productive environment. If you add a Lisp feature to a large code base, it may not take a lot of time to do so, given the possibility of an incremental development style with Lisp (-> changing running applications incrementally).