N26 Site Reliability Engineer interview questions

I apply through the website and got the first email from a bot to scheduler a screen call with the recruiter. The interview with the recruiter was pretty ok. General questions about my background, how long time to relocate and salary expectations. After that, he sent me a challenge assignment that was 100% coding. The assignment was well defined (goal, requirements, bonus tasks) and to be done in 72h. I completed ok so it took me to the next step which was 2 technical interviews, 1hour each, with SREs. The first interview was focused on the challenge that I made (what improvements I could have done, how to put on production, security concerns, etc). Also, focus on fundamentals questions about networking and security in general. The second interview was focus on practical activities. The guy describe an infrastructure that he had on his house for smart home and asked me what concerns I had and how I would improved it. I had a good expectation from this two interviews and the 2 guys were pretty friendly but, unfortunately, after that I got a email from the recruiter saying they would not move forward on my process.

One of the toughest interview processes I've ever experienced. The people in there really know what they are asking and will crush you if you try to fool them. They will, literally, extract every drop of your knowledge. Don't even think about mentioning a protocol or system characteristic which you don't truly grasp all the intrinsic details - they will ask more and more about it. A few questions about Operating Systems, but no kernel-internals questions like Google/Facebook. The main focuses are on Networking and Security (never forget they are a bank). Know the OSI Model inside out. Some questions start at the Application Layer (7) and go all the way to the Physical Layer (1). Know TCP, UDP, DNS, HTTP, SSH and specially TLS and VPN. Many questions on reliable and secure ways of transferring data. Knowing the handshake details for both TLS 1.2 and 1.3, specially their differences what is SNI/encrypted-SNI, is the least expected. Other security questions like symmetric and asymmetric private/public key cryptography. The whole process will look like: 1. Recruiter/HR interview 2. Take-home test (72h deadline, 4-8h work time) 3. Two rounds of technical interviews 4. Engineering Lead interview