Before We Begin

What it is NOT about

This is not just a list of AI-generated or copy-pasted questions from some GitHub repo.

To drill questions like "what is polymorphism?" use the Train section.

What it IS about

What this section is — a list of the popular questions companies actually ask, picked so you can show off your technical knowledge.

Questions like "What is a Linked List?" have one static answer. Again, these you can drill in train section. Companies expect you to just know it.

But questions on concurrency, microservices architecture, databases, indexes, distributed systems — that's your chance to shine and steer the conversation and show them your seniority.

This section builds intuition and understanding. It does not require only mechanical memorizing.

☕ A note on the stack. The ideas here — databases, concurrency, messaging, architecture, Kubernetes — apply to any backend engineer. But when I need a concrete example, I reach for the stack I actually work in: Java and Spring.