At work I mainly write C++, but I have a little library in CL that I've been working on for a while that can call our REST API, access and filter our log files, connect to our test infrastructure, and some other miscellaneous stuff. It started because I wanted to call our product's REST API from inside Emacs (in the Slime REPL) to make debugging and testing easier, but over time it's grown to about 1500 lines of CL to automate common tasks.

Outside of work it's my go-to language for learning new stuff. I use it for a bunch of little programming projects that I put on Github (https://github.com/jl2?tab=repositories). They're mostly just playing around with whatever topic I'm interested in at a given time. Lots of animations and (simple) computer graphics, some simple games, one or two libraries for the Raspberry Pi, etc. Nothing too exciting.

I want to start contributing to some of the open source libraries and projects (like stumpwm and sbcl) that I use a lot, but so far the few commits I've made to other projects have been really small bug fixes or trivial documentation fixes.