Two main issues:

• Ambiguous ad: While I had applied for two positions, the HR recruiter decided on her own, despite my credentials, to exclude me from one of them, even before the first call. When asked for an explanation, she justified this with very debatable arguments. The root problem was that she was looking for a senior figure, while the job ad didn't mention any level of seniority required.

• Screening interview problem: This was quite easy. In fact, it was so easy that the discriminant that caused my rejection was about how I Googled stuff or whether it took me 45 minutes instead of 30 to do the assignment, while no time limit was ever mentioned besides the total 60 minutes of the call.

All in all, despite the interview process being very efficient and quick, I can't shake off the impression that Stripe is quite an elitist/snob startup in which the hiring process can be very arbitrary and shallow.

Implement a "name tracker" to allocate and deallocate server names using a certain number convention.

OO, elementary array manipulation problems.