Java

Why is BeanPostProcessor needed?

Have you encountered the N+1 query problem? How did you solve it?

How to implement a thread-safe counter in memory?

Why is Spring needed? Why is it used?

What are the main principles of building a thread-safe class?

Have you ever worked with lazy loading? What is it and how is it used?

Have you ever optimized a NOT IN condition? How bad is it and how to optimize?

How was optimistic locking used in your projects? How did you resolve StaleStateException?

What happens if both an entity and its collection are mapped with Eager, and we load one element of the collection?

Tell about your work experience at your last job (Lekton). What did you do, what stack?

Can you imagine a task where Spring is not used?

In a class, there are two fields with an invariant (one strictly less than the other), each protected by an AtomicInteger. Is this sufficient for thread safety?

Have you worked directly with writing multithreaded code?

What is the purpose of the volatile keyword?

What happens if two threads read the same entity in parallel and try to modify it in Hibernate?

Physical question: what will happen if you jump inside a moving train?

What happens if you jump on the roof of a moving train (200 km/h)?

Logic puzzle: 9 balls, one is heavier, what is the minimum number of weighings on a balance scale?

What do you pay attention to when designing a database? What principles?

Is it permissible to violate normalization principles? Why?