I applied online. The process took 2 weeks. I interviewed at TU Darmstadt in Oct 2015
Interview
General questions about research, the topic of study, considering your CV, educations details, transcripts and certificates, questions about research done before and questions about research that will be done, interviewing by Skype is possible, and you would tell your CV, educations details, transcripts and certificates
At the first stage, I was asked to consider a problem a provide a solution. It took me 10 days. After this stage, there was an interview with thous who solved the problem. During the interview, we discussed the mistakes of my solutions and the way I solved it. The aim of the interview was to check my ability to think critically and to learn new information. Finally, I successfully got the position.