This document helps you by providing guideline for how to take an effective interview.
Domain understanding
Programming
Puzzle
Designing
(Programming +puzzle) OR (Programming +domain)
Ask basic question and then in depth (unknown and conceptual) questions
If he answers basic, then he is average
If he can answer in depth, give above average rating
Discussion with experts
Personal experience
https://drive.google.com/file/d/1zTrH8NCwc3lF1YsYGn6SyrZf3faeUz5a/view?usp=sharing