I was contacted via email after I've sent my online application for a first 30 minutes telephone interview, which was mainly about my CV, skills, motivation, etc.
Following upon one week later was a technical telephone interview scheduled for one hour. It contained of four sections: mathematics, C-programming / concepts of OOP, control theory and MATLAB/Simulink programming/functionality.
After passing the test, I was invited for a personal interview at the company, which took 4 hours and contained several interview partners from support, application, HR and team members. I got interviewed by two department leaders about my background, motivation, behaviour with potential customers as well as strengths and weaknesses. It was followed by a short talk with the HR department. Following upon was again a written test with questions regarding math, C-programming, control theory and Simulink. After meeting potential team members, I was shown the typical working environment.