The interview process was smart. I was contacted by HR after applying on hh.ru.

There were three steps in the interview process:

• Skype interview (1 hour)
• Onsite interview (4 hours)
• Take-home assignment ('homework') (1 week)

The interviewers were very professional and helped me a lot to succeed.

Skype interview topics:

• Fibonacci number calculation (effectively, exponentiation by squaring)
• Python-specific questions (context managers, descriptors, metaclasses, etc.)
• Favorite sorting algorithms and their complexities
• Big O, Omega, and Theta notations

Onsite interview problems:

1. Effective data structure for O(1) read, write, and delete operations.
2. Generating Rand(3) from a given Rand(2).
3. Sorting an array larger than RAM.
4. Depth-First Search (DFS) implementation.
5. Iterator that skips every second element (Java implementation was requested).
6. Brainteaser involving the size of a train with light bulbs.