Majorly focused on Data structures. Have very strong knowledge on it. Fibonacci series using recursive - was asked to code Stack, linked list, doubly linked list. Real time examples. Find frequency of occurrence of a numbers in a list without using collection - was asked to code Sorting Techniques Springboot Difference between spring and springboot Oauth Java 8 features- if you have used Collection Framework What ever you have hands on upon, be strong to each bit of it... Interview seems to be easy if you know the depth of concepts.