I was contacted by the recruiter and initially told I would have two rounds of interviews: one on pairing/coding and another behavioral.

This position's primary focus is on both front-end and back-end experience. Just back-end would not suffice.

However, during the interview, I was asked to design a microservice architecture and questions from the resume. I did not have a coding/pairing interview.

The interview went for 2.5 hours, touching on all architectural questions, behavioral questions, whiteboard questions, and performance-related questions.

I answered all of them and received positive responses from the interviewers during the interview. I don't know what went wrong. I got a response after two days that they are not moving forward. I am left with questions: Why!

Design micro-service architecture (nothing in particular), design patterns that Java 8 streams use, and measures that you take to increase performance of services in the micro-service architecture.