BioNTech Scientist interview questions

After 1 month of submission of the application, I received an interview invitation. It's an online interview. I was asked to prepare 10-15 minutes of presentation of previous experiences. The presentation has to be submitted two days in advance. No behavior questions. Only related to the presentation and the skills. The candidate cannot directly contact the interviewers. The only way is through HR. The HR is nice although they cannot give me feedback on my interview performance.

Phone screening with HR. A week later, a 30 minute zoom interview with the hiring manager. The next week, a second phone call with HR to go over how I feel about to process. Then a full day event where I gave an hour seminar then a series of 2 person interviews with the entire team. However, the way they handled the next steps was very unprofessional. I was told by the hiring manager that if they wanted to move forward with an offer, they would have me submit references with them to check with. The next week, they asked me for references so I assumed that meant, pending references, they were planning on extending an offer. Since I recently got out of graduate school, I have very few professional references outside of my professors. So I had some of my coworkers as references with the thought that I should be getting an offer from the verbage used in our conversations. After submitting references, they said I should hear back within a week or two if I received the offer. However, the week they said I should be anticipating an offer also happened to be the same week as a major conference in the field. And then at this point, they continually strung me along and would not extend an offer. And every week, I had to email them to ask for updates, to which they said they had one more interview to complete and should hear back within a week. Well roughly 4 weeks after the conference (about the same length of time as my interview process), they tell me that they will not be offering me the position. So my thought is that after they asked me for references, and spoke with all my references, they met someone at this conference that they wanted instead and strung me along the entire time. The fact that I could have jeopardized my current position (maybe some naievity on my part as well) to be used as a pawn is incredibly unprofessional and because of this, would not be interested in working for them in the future.