It is strange that in the technical interview there is only one person. It is a detail that already surprised me from the beginning and made me suspicious. The technical test consists of making a REST API to load a wallet by making a request to a Stripe mocketed client. In my solution i included all the domain models (UML), sequence diagram (UML) and everything included in the README.md of Git Repo itself. The implementation solution was to have a Transaction entity where you store the transaction and its state to be able to control all the situations of the charge itself. I mean, having a status machine to know at every moment the situation of the transaction itself. The wallet balance update was done with "UPDATE a = a + amount" to avoid OPTIMISTIC lock. The API consisted of a POST /transaction. I don't think that at any time they could not refute me anything about the technical solution and even at the end, I asked, to the interviewer himself, if he had seen something that was a clear alarm (to improve me). He answered me NO. This kind of situation is sobering. It is a pity since it is normal to have 2 interviewers and in this way it is very difficult that the evaluations have anomalies or are subject to subjective assessments or that may favor the interviewer himself as he rejects candidates of higher level for personal convenience. In my current company it has happened in Chief Architect positions. It's a shame. It is curious that in two companies, also from the startup world, where I have presented this hexagonal solution, I have been congratulated for the implementation. Besides, there are not many secrets.