Bloomberg Senior Data Engineer Interview Experience — SQL String Ops and a 20-Minute OOD Screen

The role was Senior Software Engineer - Data Engineering. I couldn't really find much interview experience for this role online, so let me contribute one here.

The interviewer was a woman, not very enthusiastic. 40 minutes, 2 questions — the first was SQL, the second felt more like OOD.

The first SQL question wasn't too hard logically, the hard part was that it tested string operations. I roughly knew which function to use, but for one thing, I use BigQuery at work, and the exact method naming and usage is a bit different from Postgres, which is what the interview used. In my day-to-day work I'd normally search to confirm the method name and parameters, but you can't search during the interview, so I had to rely on the interviewer's reluctant hints to piece the query together. At one point she also said something like "substr should be a pretty commonly used method," blah blah. In the end I fell a little short.

The expected SQL looked roughly like this:

The second question was Python, and I was still a bit thrown off from the first question, so my reaction was slower than it should've been. The question was long — the example code on the right was almost 200 lines — and I was only given under 20 minutes. If I'd been writing it from scratch I could still have gotten somewhere, but this question wanted me to add an implementation into an existing class structure shown on the right, and the code included abstract methods, which made it easy to get confused. In the end I could only talk through my approach out loud.

A pretty ridiculous experience overall — I prepared for 3 weeks, and it turned out the recruiter's description and what the interviewer actually asked were completely different. Felt a bit scammed. The recruiter had told me it would be easy-to-medium coding questions.

For the data eng roles I've interviewed for elsewhere, SQL didn't test this much string manipulation, or the interviewer would give hints pretty readily. As for the coding part — companies like Stripe and Instacart that test OOD-style coding at least give you 30 minutes, and the questions aren't this long.