Datadog interview questions

Applied online for a senior software engineer position. Ad specified a github account with an open source project was needed (red flag #1) - I have none. I got an email (not a telephone call - red flag #2) 15 minutes (red flag #3) after sending my resume. I scheduled a phone screen for some days after. The phone screen was not a screen at all (red flag #4), just a way of checking that my English was fluent enough for a phone interview. The phone interview was a classic Cracking the code interview with two easy questions, but before that I got questions about things that I had done (microservices and nosql) showing that the interviewer had not done those before, quite strange for a self-described "cloud company" (red flag #5). Very soon afterwards I got a "code challenge" test to "prove that Datadog's problems were interesting to me". The code challenge was about a problem in the domain of Datadog's, not difficult, but in a way that implied having to write quite a lot of code instead of proving my ability to solve problems (red flag #6). I agreed on a timeframe with the recruiter and delivered it way before it was due. I wrote exactly the code needed to solve the problem, and a few days later I got a rejection email - no discussion about code, no additional questions - like code is something that you magically get right the first time, totally optimized, having mind-read your stakeholders' mind - a lot of antipatterns here. It was a slow time at work so I didn't mind the absolute waste of my time, plus it's a lot of important lessons learned.

Recruiter phone call, technical screening, homework assignment, in-person interview, long wait, then they changed their mind and the position wasn't really available in my location after all. The logistics of the in-person interview were impeccable. One meeting was with 2 current junior SREs. The junior employees were not very comfortable running the interview. Another meeting was with a senior guy who ran a very good interview. The last was with the CTO, who ran the best interview of all, really giving a clear idea of what he wanted to know and leaving me room to sell myself as I wished.