first half hour Java versions difference whats introduced in java17 java11 vs java8 what is need of dependency injection in springboot autowired vs qualifier manytoone, onetoone, onetomany annotation in @Entity class n+1 problem behaviour of object class in java (wait, notify, etc.) second half hour merge overlapping intervals even when you answer all theory questions and write optimized working code you get same standard mail. Doesnt look like they are actually interested in hiring, waste of time.