Java

What was the RPS at the peak? How many were recorded?

Can any object be added as a key in HashMap?

Senior

Альфа-Банк

How to implement rate limiting for an external API with RPS restrictions? How do virtual threads/coroutines differ from system threads?

Senior

Ozon Финтех

Provide an example of a technical improvement in a project beyond business tasks.

What is the difference between Kafka and RabbitMQ?

How to read a specific header (for example, badge number) in a controller?

Senior

СБЕР

What approaches are there to handle unstable integration that may not respond from a minute to a day?

Have you ever written a BeanPostProcessor? For what purpose?

Middle+

Т-Банк

Was the order of events in Kafka important? How was it ensured?

Senior

Альфа-Банк

[Name] asked: Did you work under an employment contract?

Middle

СБЕР

```java // 2 public class Interfaces { public static void main(String[] args) { A a = new A() {}; B b = new B() {}; AB ab = new AB(); a.print(); b.print(); ab.print(); } public interface A { default void print() { System.out.println("interface A"); } } public interface B extends A { default void print() { System.out.println("interface B"); } } public static class AB implements A, B { } } ```

Senior

СБЕР

Tell me about the SAGA pattern: orchestration and choreography.

Senior

СБЕР

What type of index should be used for searching in the middle or end of a string (LIKE '%text%')?

Are indexes needed in this task and on which fields? What indexes are created by default? From which version of PostgreSQL is an index on foreign keys automatically created?

What are the advantages and disadvantages of TimescaleDB compared to Postgres?

Is it necessary to wrap the transferMoney method in @Transactional and why?

Middle+

Ozon Финтех

What is the MVC pattern?

What is the main problem of this implementation - Connection to Redis is hardcoded - There is a connection pool for Redis - Unverified call to `jedis.get` may return null - Using the `KEYS` command causes server load - No Redis events

What is the main problem of this implementation - Index may not be mandatory - Incorrect index type used to achieve the desired goals. - There is a composite index - The table is not normalized - No use of transactions

[имя] спросил: Как снять heap dump с Java-процесса в Kubernetes? Опиши по шагам в bash-консоли.