The HR told me to prepare for a Control theory interview so I reviewed this field for a few days . At the interview they asked me about electrical motors (DC brush, brushless and servo), they asked superficial questions about charecteristics that I could have found on Google. There was one question (very basic) about control theory and thats it. Most of the time they wanted to ask me about electronics and electrical engineering questions when I was clear about me being mechanical engineer geaduate with little experience on the field.