Many years ago software for CNC machines.
Then software for other areas - distributed applications with communication via LAN, RS485 and CAN. Programming in Delphi under WINDOWS. After the end of WINDOWS-7, switch to LINUX (Deepin) and LAZARUS. Never again WINDOWS10!

C only on ARDUINO -IDE for ESP8266.
ATMEGAS mostly in assembler
Rapberry (Debian) and Lazarus commercial application. (own super-fast graphics and own fast GPIO driver for frequencies in the MHz range)
Today retired and programming as a hobby