N26 Java Developer Interview interview questions

The interview process had the following rounds 1. Introductory call with HR 2. Hackerrank Coding Challenge 3. Live Coding Interview - 45mins 4. Technical interview with Team Lead - 60mins 5. Interview with Team Manager - 45mins After the call with HR, I was given a code challenge to implement a REST service to hold the transactions and calculate statistics. I submitted my solution in two days. I was selected to the next round of live coding challenge which happened via hackerrank code pair. I was asked to write code to find the first unique character in a string. I was told that I cleared this round and an interview was scheduled with Technical team lead. This interview mostly had open ended and general questions around microservices and monitoring. After this round HR communicated to me that they got positive feedback and a final round with Manager was scheduled. This round as well had many open ended questions. After all these, HR came back saying they cannot extend me an offer because I am not good in DevOps, multi threading, automation testing knowledge. To my surprise I was not tested on multi threading in the interview process at all and going through my resume they could have easily known that I have no experience in devops instead of wasting several hours of my time. Also I did not understand what level of knowledge they expected me to have on automation testing as a java developer.