TikTok Intern Backend Software Engineer Interview Experience — Two Rounds, an LRU Cache, and a Cold Interviewer

Overall, the entire interview process was okay and was not difficult, but I was very disappointed with the second-round interviewer. From beginning to end, that interviewer had a cold attitude, was not very willing to help, and asked questions that were not very clear. I heard that interviewers at TikTok are assigned randomly, so if you are unlucky, you can end up with a poor interviewer. The first-round interviewer was pretty good.

Although I was rejected, I wish everyone a smooth interview process!

First-round interview:

I was asked about my resume. You need to prepare this carefully because the interviewer asked very detailed questions. For example, he asked which of my recent projects I thought had been the most difficult. We then started discussing that project, including why I used that technology stack and how I would scale the project.

He also asked me some database questions, such as why we need indexing and why we cannot index every column.

Coding:

The problem was exactly the same as LeetCode's LRU Cache.

Second-round interview:

The first part was the same as the first round.

Coding:

Design a hash map.