I was once on a job interview there, in the Train/Station Wifi branch, mostly web programming related though IIRC. It wasn't so much of a quiz format but the interviewers wanted to know what I worked on before, why I wanted to change etc. What really stuck with me was how the department CTO insisted how superior and privacy conforming their logging system is. Not saving anything, not even for a micro second. I didn't dare to ask how they debugged anything. But in the end I was rejected and the reason was: more questions than answers.

It's negative selection applied to you. And you have dodged a bullet here.