Primer Frontend Developer interview questions

The interview process was quite lengthy: initial interview with the recruiter, tech challenge, tech challenge review and probably one more but only got to the review stage. Overall people I interviewed with were nice, however the tech challenge was too long. I spent several days working on it and I really think it was not necessary to include that many functionalities to get a good grasp of the candidate's skills. Since the process was lengthy and demanding I expected at least a decent feedback at the end of it, but it was very general and not that constructive. What's more I have an impression that they have extremely specific expectations towards the candidate which were not included in the job description. It would be fair to communicate these clearly so both sides do not waste their time.