I had around 6 exp as backend developer and working on scalaable systems.
1st : Telephonic : This overall interview included architecture, databases, scalability and thought process questions and was conducted by some senior guys.
2nd : Assignment : This was based on problem statement related to building Rest apis and had different considerations like scalability, speed, code quality and optimization. Again this was evaluated by some senior guy.
3rd : Telephonic : This was very horrible, as it was conducted by some 3 yrs exp junior guy and he had knowledge of only one language and he kept asking questions for single javascript langugae, he went so deep and was asking about such minute things which rarely 1% people might have used.
If you are hiring someone for above 6 yrs exp and want him to be jack of all trades, you cant just evaluate him on single languages all syntax and features nitty-gritty. No one knows any langugaes 100% everything if they have never came across situation require to use those.
Interview should never be langugae constrain, it should always be related to thought process and logical.
Any one can google and learn minute of language if required during development.
Overall this round was more for NOT-TO-HIRE and negative round.
Best advice to anyone appearing for such interview would be stop interviewer immediately and ask him does he really want some smart guy or just someone who mug ups language syntax.