Without a dropping a resume...I do back-end in Java/Clojure, React based front end. Domains include automated file transfer and telephony. I can learn whatever if it doesn't require a PHD.

Honestly, my passion/interest/strong suit is tackling problems that matter, and if that involves using a broad swathe of my skillset, all the better. Clojure is probably my favorite language, but I don't fetishize any particular technology. For what it's worth, I don't mind/actually like working on crunchy old legacy code. Often a lot of the business value is tied up in that, and someone has to know how to get in there and make it work.