I'm an electrical engineer of 20+ years in scientific and medical instrumentation working on circuit design, schematics, PCB layout, and troubleshooting. I have R&D and Manufacturing experience. I have worked analog and digital designs.
My most complex design was a 5 channel analog board receiving current pulses from avalanche photo diodes and converting them to voltage read by ADCs. This board had linear and switching regulators, and a high voltage power supply. It had a Quartus II FPGA, TI DSP, Xilinx CPLD, and USB.
I've also designed a capacitive level sensor used to detect the liquid level in a well plate in an In-Vitro Diagnostic instrument.
This is a bit of a reach for me, but this is why I do side projects. I do them for the experience and exposure to new ideas (new to me).