Simple HR 20 minute phone interview, which was pleasant and easy. Then a week later I scheduled a 40 minute technical phone interview. Fairly basic questions -- what are linear differential equations, explain exception handling in C++, talk about the Z transform how to determine if a signal is causal.

There were three phases for recruiting procedures. The first stage was a brief and relaxing conversation, the second stage was about technical things and hiring manager asked several questions in the third stage.