ERP Consultant

How to deliver messages to all 4 instances with a 2-partition limit? Standalone consumer pattern

Tell me about indexes in databases: what types are there, when is an index ignored, and when does the database perform a sequential scan?

How was the typing indicator implemented?

How many simultaneous connections did one instance hold and how did they scale?

How long can you take for lunch?

How do you handle a slow consumer — a client that does not read messages?

Is it possible to run a synchronous requests non-blocking in an asynchronous application and how to do it?

There is a task to store data in cache and in a database for 10-30 minutes, while the database grows. How to solve the infinite growth?

How to start an operation at the beginning of a method, perform other actions, and then wait for the result of the first operation?

How does Schema Registry in Kafka work and why is it needed?

Tell me about garbage collectors in Java, what types are there, and if you have experience configuring JVM.

Which classes in Java are not inherited from Object?

What microservice design patterns do you know?

Tell us about your last project: what did you do, what were the tasks, projects, and tech stack?

How did you solve the problem of a hot dialogue with a thousand messages per minute?

Tell me about interfaces and abstract classes: when to use one, when to use the other, and inheritance features.

What approaches were used in microservices architecture and how was the interaction between them built?

How was the database partitioned for storing messages?

How did you ensure the atomicity of operations and deduplication of orders when working through Kafka?

What was the internal architecture of the backend service: modular monolith, DDD, MVC, or another approach?