Java

What is SKIP LOCKED and how does it work?

How does Read Committed work inside PostgreSQL?

Between which elements do Kafka delivery guarantees work?

What GoF patterns do you know?

How to add logging to all methods of the old service without changing the business logic?

What does Kafka guarantee when using a consumer group with three partitions and three consumers?

What is SELECT FOR UPDATE and SELECT FOR SHARE? What is the difference?

What isolation level is most commonly used with SELECT FOR UPDATE?

How can two transactions be created in one class (bypassing self-invocation limitation)?

How does Kafka achieve the absence of duplicates within a consumer group?

What methods of thread synchronization do you know in Java?

Method one @Transactional calls method two @Transactional(REQUIRES_NEW) in the same class. How many transactions will be created?

Can we use mechanisms other than versioning in optimistic locking?

How to implement business logic validation in Spring (e.g., age >16, no blocked accounts, card limit not exceeded)?

Annotated method with @PostConstruct and @Transactional. What will happen first?

How does optimistic locking with the version field work? Explain in detail with an example of two transactions.

What thread pool is used under the hood of Stream.parallel()? How does ForkJoinPool differ from FixedThreadPool?

What is the relationship between topic and partition in Kafka?

What levels of message delivery exist in Kafka?

SELECT FROM A RIGHT JOIN B — how many records will be returned if A has 10 records and B has 100 records?