I applied online using the viessmann.de job portal. The job application process is very simple and you just need to send cover letter and CV. I received an interview call the next day. The job was very relevant to my internship I was doing at that time; almost the same work and same skills. It exactly matched my profile. I did all the application in English although the advertisement was in German but it only mentioned for the candidate to have good English skills. I have some skills in German so I thought its okay to apply. I applied and got an interview call the next day. I prepared for the interview and took break from work. The interview started and the lady asked that before starting the interview, tell me how are your German skills to which I replied that I have some skills A2 level but she immediately said sorry we cannot start this because we need someone with native German fluency. But they should have indicated on the job advertisement and I have already specified in my CV my German skills. I understand but it should be clearly indicated in the job description. I was disappointed because I was excited to have this interview because it matched so perfectly with my profile.