Amazon Software Development Engineer SDE interview questions

DSA heavy and focus on core concepts. System design and projects were also asked. But the interview process is slow, was reached out by the recruiter multiple times but interview took a lot of time.

What are the four pillars of OOPs in Java? Explain each with an example. (Abstraction, Encapsulation, Inheritance, Polymorphism). What is the difference between an abstract class and an interface?. Explain method overloading versus method overriding. What is a constructor, and how does it differ from a method?. What are the SOLID design principles?