I've been having a lot of fun building out, and playing with uLisp. I enjoy adding low level functionality in C, and then interacting with it at the uLisp REPL. Very satisfying.
I really wish there were a handheld device like the Precursor, or Solder Party Keyboard Featherwing[0] that was available in a robust form factor, like a graphing calculator, or wedge keyboard. Ideally with a Teensy 4.1, or similarly spec'ed microcontroller. Bonus points for a LoRa module for messaging/mesh networking with other devices.