1. Found the opening on LinkedIn and applied.
2. A tech recruiter from the company contacted me. We had an initial interview going over my CV, experience, and my salary expectations. The recruiter said that my expectations were within both the senior and mid-senior ranges.
3. After over a week with no more movement from the company, I received an email from the lead tech recruiter asking why I had not moved forward with the process.
4. I responded saying that the initial recruiter had not taken the agreed step to schedule a new interview.
5. The initial recruiter apologized for "having lost my data in an OS upgrade" and scheduled the next interview.
6. I had the interview with an engineering manager, covering past experiences, tech stack, and behavioral questions.
7. I passed that round and received a take-home tech challenge where I had to build a server capable of taking 2M+ TCP connections every 10 seconds.
8. I completed the challenge and submitted it as agreed.
9. I received a request for a follow-up interview to cover the implementation details and do a systems design whiteboard exercise (2h total), which I did and it seemed to go well.
10. Time passed (2 weeks) and I received no feedback, so I asked the recruiter. He got back to me saying that I passed all the filters and now they need to do some internal talks to make a final decision.
11. Another week went by and I received a rejection email literally saying that I am not a good "cultural fit". No feedback or anything besides that. Very poor and inconsiderate, taking into account the amount of time I had spent on the process.
12. I sent an email asking for better feedback in order to improve and grow, and have not received a response.

Behavioural, system design whiteboard exercise.