I use it in my day job. We use it to write sensing and machine-control systems to reason about the data from telemetry, neural nets, and machine-learning systems, to compute strategies for those components, to compile the strategies to native code, and to control and coordinate the component systems.

We also use Python, MatLab, shell and bat scripts, C#, and C++. I work in all of them, but I use Common Lisp for whatever I can.