Analog/Digital circuit design. 40 yrs. Mostly low freq (< 1 Mhz work)
Use PIC microcontrollers often, to reduce floorspace and add capability. Some low level CPLD and FPGA work, if needed.
Motto: Apply the 80:20 rule, twice. That gets you to 96 %. Dont let perfect be the enemy of very good.
Working in electrical engineering education creating remote access electronics labs for EE departments for undergraduate study.