Python

Tell us about your specialty: how did you choose it, and why did your journey in IT begin?

How to update a high-load microservice to a new version without losing requests? What to do if the database migration breaks the old version?

Senior

Совкомбанк

SQL task: how to retrieve users with names in Cyrillic and Latin, sorted so that Cyrillic comes first, and within groups lexicographically?

Middle

СБЕР

What is a context manager and why is it needed?

How is memory organized in Python? Tell me about arenas, pools, blocks.

Tell me more about your last project: what you did, what tasks you performed, what was your area of responsibility.

Do you have practical experience with Kubernetes or just basic familiarity?

Why are authentication and authorization separated? Can you explain?

Why is denormalization needed in a database?

[name] asked: How many queries would be executed in the database if using select_related, and how many if using prefetch_related?

Senior

ivi

What are the ways to resolve collisions in a hash table?

What large and complex task in [company] can you highlight as giving a boost to your development?

What happens to memory after objects are freed (for example, closing a large file) — does Python return it to the OS or keep it?

[name] asked: If the call count information is stored in a closure via nonlocal, how can I find out outside how many times a specific function (e.g., a) was called?

Senior

ivi

Tell us about the services and work at your last job — pick a couple of features and tell how you solved them from a technological perspective, what patterns you used, what difficulties and alternative approaches there were.

Besides cp, what other way can you transfer a file between servers?

Have you used the Prefetch class (with a capital letter) with prefetch_related?

Compare the architectural approach of Django and FastAPI. What architecture did you use in your FastAPI project?

Tell me about garbage collection in Python: what it is and how it works.

```python from collections import Counter def min_s(a: str, s: str) -> str: need = set(a) window = Counter() res = "" c = 0 left = 0 best_len = float('inf') for right, char in enumerate(s): if char in need and \ window[char] += 1 if window[char]: c += 1 while c == len(need): if right - left + 1< best_len: res = s[left:right + 1] best_len = right - left + 1 if s[left] in need: window[s[left]] -= 1 if window[s[left]] == 0: c -= 1 left += 1 return res ``` The task is to implement a function `min_s(a: str, s: str) -> str` that finds the minimum substring in `s` which contains all characters from string `a`.