A face-to-face interview is not uncommon, even for work placements. Since it’s simply impossible for applicants from North Africa or the Near East to travel to Germany for an interview, it’s important to ask in advance whether it is possible to conduct an interview via Skype or another video chat channel. Most HR officers will understand that. However, a remote interview is not very different from a face-to-face one.
Appear in person (HR officers are professionals; they will realize it if you are trying to deceive them).