The process took one month and a half:
The first interview went well; classic questions (i.e., which studies would you pick if you had to launch a new product, questions were practical-oriented.)
HelloFresh offered me to attend the 2nd round of interviews and demanded my time availabilities. They took one -month to coordinate the interview (coming back to me after sending an email to the HR). They asked me to solve a case (2 questions, broad topics on evaluating the brand performance and launch of a product.) I did the case (approx. 72 hours of work/30 minutes of presentation). I presented it to the hiring manager, the N+1, or any other team members who couldn't attend the meeting. I got a refusal answer without any feedback as if I didn't pass the first round of interviews. I asked for feedback; I am still waiting, and it has been three weeks from now.
I think HelloFresh can be ashamed of its hiring process. Even though they receive many candidates, hiring people shall always remember they face humans in interviews. People deserve respect.