I applied online. I interviewed at Falck (Warsaw, Masovia)
Interview
30 minutes online interview with two people. First person asked about current role and job experience, the second asked a few behavioral questions and a few technical questions about SQL and Python
Interview questions [1]
Question 1
Is Python a hard or softcoded language Experience with cloud How to deal with long-running SQL queries Biggest datasets I've dealt with
I applied online. The process took 2 weeks. I interviewed at Falck (Copenhagen, Capital Region) in Aug 2023
Interview
Initial call was supposed to be 30m online "an initial screening call to discuss the role, your background, and your expectations" which turned out to be just a series of mostly SQL questions from two DEs. Whereas the job description said "It is great if you have SQL experience, however we are looking for a candidate who is good at and enjoys thinking out of the box", I was asked about concepts related to database administration, query optimisation, modelling. All in all, I don't think the questions were that difficult but I was surprised I had to do this when I had prepared for something completely different. I could have maybe done better had I received information that was more aligned with reality. Also the JD made it seem like an easy going role where some SQL is nice to have but these people were interviewing as for someone who had been designing databases and DWs for quite a while now. A learning experience for me: try and ask beforehand more information about the process and the job, lest you come unprepared and fail.
Interview questions [1]
Question 1
What can we do to optimise a slow running SQL job? How do you remove duplicates from a query using window functions? What is a dataframe? Do you know Kimball? Why use a surrogate key? What are some types of indexes? What is a pull request? How to flatten an arraw of Jsons with specific method in mind? Why normalisation vs denormalization? Why use a Snowflake schema instead of star schema?