* for native software For microcontrollers, my go-to is a debugger (for complicated/large code or when real-time trace is needed e.g. moving parts) or blinky L

* for native software For microcontrollers, my go-to is a debugger (for complicated/large code or when real-time trace is needed e.g. moving parts) or blinky LED (simple code or tight memory constraints). print() is pretty far down on the list unless I'm flashing via USB and also already using serial communication. Disclaimer: I build hardware debuggers and am obviously biased.