Golang

What types of transactions (isolation levels) are there in PostgreSQL?

What is observability? What are the three pillars of observability you know?

Tell about optimistic and pessimistic locking. How do they differ?

Tell me about the daily payment calculation system — what kind of system is it and how was the calculation done for 50 thousand employees?

/* You are a writer, running your mini blog and publishing articles there. Your blog users (readers), after authorization, can view/read them. Implement functionality to count unique views per day for each article. Functional requirements: - Today's statistics: The author can see how many unique users viewed their article today (data is accumulated in real-time). - Past days' statistics: The author can see statistics for any past day (for yesterday). Technical constraints and conditions: - The application runs on 1 server (1 pod) - Storage in memory - Time in UTC0 */

If there are 2 consumers and 4 partitions, how will the partitions be distributed?

Tell me about the GMP model in Go. How do queues work, what is handoff, work stealing, netpoller?

What is inline compiler optimization? When does it occur and how does it affect variable placement?

How was the repeatability of calculations guaranteed — that the same conditions applied to the entire group of employees?

How did you determine where the bottleneck of a specific request is?

What is partitioning and sharding? Have you used them?

How have you worked with transactions on shards? How did you ensure consistency?

Why was gRPC chosen for the aggregation service in this case?

How does Go decide to allocate memory on the stack or heap? Why is this important?

How does Kafka work? Tell about delivery guarantees and idempotency.

Tell me about developing a custom log parser (a wrapper over OpenTelemetry). What was your role?

How does the rule engine work?

What is MVCC in PostgreSQL?

What exactly was cached and what invalidation rules were used?

Is it possible to use a composite index (A, B, C) when filtering only by column B?