Interview went well, all the three rounds were good and done on a single day. first and second round was only ds algo, third round was low level design round. but received rejection at the end of the day.

They had very Junior people screening the applicant in coding and design round. I coded in Scala but eschewed advanced features. So code was like java performance only, still they took ages to agree the design. Interviewer had no knowledge of visitor pattern. In the design round I answered the high level design pretty well even went into Scalability and concurrency issues. But interviewer was only interested in databases query syntax. When I mentioned I have never worked on them, he abruptly left and the hr came in and mentioned I needed to brush up on the basics. If they wanted dB experience they should have clearly mentioned or taken the time looking at applicants cv and not wasted both our time