Embedded / IoT

Tell me about working with PostgreSQL optimization — what did you do with indexes and transactions?

When does an object get into the heap in Go?

1. What client (user) features have you implemented in the last year at your current job? 2. Approximately what percentage of tasks in the last year did you implement directly in PHP? 3. What PHP/GO ratio would be comfortable for you in tasks at a new job (approximately in %)? 4. Why do you want to change your job? 5. What is your experience in commercial development in GO? 6. Have you had experience with REST RPC, gRPC, API? 7. Do you have experience developing services in Kubernetes? Deployment experience? (Describe on which projects) 8. Do you have experience deploying Unix-like operating systems? (Describe what you had to do) How do you assess your Linux OS knowledge level? (user/advanced). 9. Do you have knowledge and/or experience working with terraform? (Describe on which projects you used it?) 10. Have you worked with PostgreSQL, MongoDB databases? 11. What income level are you considering? 12. How many years have you been working in commercial development, and how many specifically with Go? 13. Do you have experience developing games or mobile applications with gamification? If yes, attach a link to the project. 14. Briefly (3-5 sentences) describe the architecture of the last Go service you designed or significantly changed. What components, why this structure, what would you do differently now? 15. Tell about refactoring or migration that took more than 2 weeks. What was the trigger, what metrics were before/after, what went wrong? 16. What AI tools do you work with when writing code? What have you changed in your AI usage in 2025? 17. Describe a case where using AI significantly simplified your work or saved time. 18. Tell about your experience working with WebSocket or other real-time solutions. In which product did you use it? How many concurrent connections did you hold, what were the scaling issues? 19. Do you have experience working with queues (BullMQ, Kafka, RabbitMQ, or others)? In what tasks did you use them? 20. Describe a case when tests caught a bug before release or when lack of tests led to a problem. What was this case? 21. Tell about a bug or incident in Go that you debugged the longest. How did it manifest, how much time did it take, what was the cause? 22. Please specify the maximum RPS or MAU of the product you worked on. If possible, also specify the p99 latency you maintained. 23. Here you can attach a code example (link to document/pastebin) or a link to Github. 24. Please, if you did not respond to a vacancy on HH, attach a link or a resume file. 25. Free comment field where you can write anything you consider important!

There are two beans. How to select one of them by default?

Describe the idempotency mechanism of debit operations: where was the key stored, what was the TTL, how were collisions handled?

What is Kafka and how does it differ from RabbitMQ?

Is the map stream-safe in Go?

What volumes of data were ingested into ClickHouse? From where? What was the RPS for reading and writing, including in batches?

Tell me about the Go scheduler (MPG model, work stealing, handoff, etc.)

Candidate's questions to the interviewer: how is the code review process organized and what is GraphQL Mesh in your project?

What is the difference between pessimistic and optimistic locking in PostgreSQL?

Tell me about the CAP theorem: what is it about, examples of databases?

Tell about your work experience.

What is the difference between Dependency Injection and Dependency Inversion?

What is the difference between WHERE and HAVING?

Describe the scheme of parallel subscription extension: topic, partition key, number of partitions, and consumer instances.

Why did you leave [company]?

Tell me, are there 6 Go developers, 2 front-end developers, 2 QA, and a PM in your team?

If beans are declared via @Configuration and @Bean, how does @Qualifier work and what is the bean's name?

What isolation level should be chosen to prevent overbooking only through the isolation level?