[chaboud]

Jr./Sr./PE is just a strawman for illustrative purposes. No ranking aspersions intended... In order I've been SDE, Sr. SDE, Senior PE, Sr. SDE, PE... It's pretty meaningless outside of the scope of one company's system.

There are plenty of hardware/software systems out there that leverage thread priority to keep low latency operations humming along (e.g. clearing a hardware FIFO) or keep background operations out of the way (ish) when the system is heavily loaded.

The interactions between threads are often sparse and directional (e.g. producer/consumer) in a reasonably designed system. Needing to play with priority to govern the interaction's between one's own internal thread boundaries can be a bad code smell. Using it to better satisfy external restrictions (e.g. user input, hardware interaction, callback handling) isn't too uncommon if you want to maximize the utility of your hardware.