There was a 90-minute online test, which consisted of 2 problem-solving questions and 4 MCQ questions.

After that, I had 2 on-site interviews.

The first interviewer failed to break the ice and seemed inexperienced. She asked a classical problem-solving question but remained silent throughout the problem and hardly confirmed the solution when I finished. After that, she asked many machine learning-related questions.

The second interviewer was very nice, helpful, and friendly. He asked 2 very good, fairly difficult problem-solving questions.

Reverse a single linked list.

Apply SVM classifier to the following plot.

Given a binary tree, calculate all the frequencies of the sub-tree sums. The sum of a sub-tree is the sum of its left sub-tree, its right sub-tree, and its own value.

Design a stack that pops the most frequent element instead of the top element. Can you do it in O(1)?