Personio Backend Engineer interview questions

Very bad experience, the first call with the RH was quite nice she was very polite and smiling. Then the other interviewers were very cold and arrogant. They asked me to do a technical challenge at home, they said it could be done in few hours, honestly I am not the best developer in the world but few hours to solve this kind of challenge is quite hard. I had to implement a graph, use an adjacency list and use a Depth-First Search. All my solution my fully tested and in an hexagonal architecture. During the review one guy confessed he did not know about what the test was about and where not familiar with Kotlin (I was applying for a job in Kotlin) I asked more feedback about my code and how I could improve the graph and if they had any complexity constraint but they had no clues. The only questions they had were "why am I throwing a Domain exception in my Application layer? (I guess they think it's bad to do this) and why all controllers were in a single file (sorry I did the challenge on my spare time and I can't afford to spend all my free time on it, + the code was working fine and was efficient. Then I go an email saying they refused my application because the code did not match they quality expectation, and offer me to do a meeting to have feedbacks)

- Brief discussion with recruiter about the company itself, high-level overview of role and talking about my background and interests, etc. - Half-technical half-cultural interview with engineering manager where we talked about past experience, interpersonal skills, etc. and also worked through a technical problem together where a few questions were raised, etc. - Coding Challenge: submitted the results then had a review together with a peer and a manager present, going through the code and talking about some points about the submission - A peer interview, mostly cultural with two peers from engineering - Another cultural chat with someone outside engineering - A small chat with a Co-founder (CTO in this case)