Golang

We all know that only those who do nothing make no mistakes. Tell us about a memorable fail in production: what went wrong, how you fixed it, and what lessons you learned?

When is it better to use a cross-process blocking mutex, and when to use a thread-safe structure like Sync.Map for working with collections of maps?

Who makes the decision to rollback?

Senior

OZON

Have you worked with more than 15 tables in a database?

What is the time range for the efficiency of operations with slices in most cases?

Have you created a database for processing requests in synchronous or asynchronous mode?

Junior — Middle

СБЕР

What distinguishes a process from a thread in terms of memory management and how does it affect their interaction?

How does the OS scheduler manage the execution of a function that performs a network request?

Can you change the number of waiting threads in a synchronizing group in Go during program execution?

Explain what the Counter metric means in the Prometheus monitoring system.

Junior — Middle

СБЕР дейвайсы

What delivery guarantee mechanism was used in Kafka at your previous workplace?

Junior — Middle

Сбер Контакт

Can you explain how the task scheduler works in the system?

Junior — Middle

Mail.ru

What happens in the network when you enter https://wildberries.ru in the browser? Describe the DNS resolution process.

Middle+

Ozon Финтех

Tell me about your current project: what are you working on, what are the main tasks, and what is the technology stack?

What is the role of goroutines in managing asynchrony and parallelism in Go?

What are the advantages and disadvantages of using column-oriented databases?

Is it necessary to add a return after logging an error in the handler when validation fails?

Senior

2gis

Can performance improvements be achieved when traversing data by using slices instead of a map?

What are MFA and SSO? How does Single Sign-On work?

What criteria do you use to understand that you have done your job well?