I had three interviews in English.

The first was about WhatsApp's system design, with medium difficulty.

The second involved manipulating strings to adhere to a formula that seemed to come from the depths of hell. It was generally of medium difficulty, but I couldn't finish it on time. I got confused and thought it was something entirely different, but it was possible to complete within the time limit.

The third was to reverse a binary tree with some extra complexities proposed by Lucifer himself. This was extremely difficult, but I managed to complete it by focusing my studies on trees.

Tip: Study the easier topics as well, because if you get the difficult one right and miss the easy one, you'll feel worse.