It was made in 3 steps: 1-on-1 professional background interview, technical oral interview and a coding test. The toughest one was the last one, but I was told I was better than most candidates, so I passed it.
I applied online. The process took 3 days. I interviewed at Klarna (Stockholm, Stockholm) in Aug 2021
Interview
After applying, they contacted me about the coding test. The coding test consisted of two questions. The interesting point was that after you completed the solution, it was waiting for you to write unit tests for the solution you developed. So I'd say it was a test focused on TDD.
So far everything was great. The questions were not extreme. My answers were not excessive. At the same time, I wrote the unit tests in a way that includes edge cases because they expect you to write production ready code.
However, after finishing the second question, I realized that one of the unit tests of the question is completely wrong. It expects a wrong output from the method you wrote. I noticed that, of course, after I (so to speak) “hacked” and debugged the unit test. I wrote the correct ones and detailed the problem in their end and submitted.
Two days later they came back with a great response: "They didn't like the code I wrote for the second question". But there's no logical justification! If you say you don't like something, you have to express problems and offer solutions. If you're just saying it's bad, I'm sorry it doesn't work that way. Also, the second question you asked doesn't even have running correct unit tests. It's like a joke!
You asked a question that had the wrong unit test. I explained to you in detail, articulated the problem, and wrote the correct ones. Look at the response I got. Enormous.
I applied through an employee referral. I interviewed at Klarna (Stockholm, Stockholm) in Jun 2017
Interview
Since I was not based in Stockholm when interviewing I had mostly phone interviews and then a final round of a set of local interviews.
Phone interviews were: HR, Hiring manager, then one with 2 fellow engineers.
Local interviews were: 2 occasions of 2 engineers, going through coding excercises and architecture discussions, and finally with the engineering manager for the team.
Interview questions [1]
Question 1
(Just like in most interviews I've bumped into lately, this question was asked here as well:)
What's one project that you're most proud of?