I got a call from the hiring manager out of the blue and he asked me about me and some technical questions regarding projects I made. After about 15 minutes he said thank you and hung up. About a week later he called again to schedule a face-to-face interview. The initial questions were, according to the hiring manager, "warm up questions" that are meant for emmbeded SW engineer (which I'm not) so I didn't really know how to answer. Second question was pure algorithmic question which I didn't do so well in.