I currently design software and hardware for custom high end automotive builds, including interconnected custom CanBus modules for controlling various aspects of automotive systems.
I use Eagle and Fusion360 to design custom boards based around SAMD51 microcontrollers, using C++ for the firmware. Java and JavaFX is implemented as a front end for communicating with the modules, pushing firmware updates, datalogging, and real time tuning of module parameters.
When I'm not 'working' if you could really call how I passionately spend my time doing something I love, I'm calibrating engine management systems, or navigating for my buddy in an off road race.