A contrary anecdata - I've worked at a bunch of places and know people who work at others that have large, actively maintained, decades-old systems using, e.g., Perl. The only one I know that was actively trying to migrate recently was looking at node instead.
If you're able to share, I'm curious what kinds of systems these are (and also, I guess, how development velocity compared to statically typed projects you've worked on).
Net-A-Porter is probably the prima Perl in London at the minute and have been for decades - although I think they started migrating to Modern Perl with microservices in 2018ish.
Photobox were still on a 10+ years old Perl system in 2018 when I left - development velocity there was only really hampered by an insane belief that rewriting into node.js microservices would solve every problem and the ORM + Object system being a ~10yr old handcrafted abomination from someone who had left 5+ years ago.
Can't speak for NAP but Photobox was extremely strong on unit + integration testing. IIRC, a full ground-up test suite run took a few hours because it started from a bare box, installed + tested Perl + every needed module, span up a blank database, then did the unit tests, then ran a full integration test suite against that server. That was only done for a release; for general commits, it was ok to run a subset of tests to show things worked / still worked.
