I applied through an employee referral. The process took 5 weeks. I interviewed at TikTok (Los Angeles, CA) in Dec 2020
Interview
First a very hard OA with 4 questions. Maybe more than 2 hard questions which cannot be seen anywhere, but you do not need to pass all questions to get an interview. Then 3 tech interviews via zoom . All about coding. About 2 question per round. No machine learning questions in any round.
Interview questions [1]
Question 1
Permutation with a follow up, how to deal with the duplication. LRU (you cannot use package).
Surprisingly straightforward — I expected a tougher challenge for a machine learning role. After a quick recruiter screen, the first technical round focused on implementing K-means clustering, which felt familiar. Handling edge cases for empty clusters was tricky, though. What really helped me prep were the algorithm explanations on PracHub, which gave me confidence going in. The final interviews were a mix of problem-solving and behavioral questions, and in the end, I received an offer that I accepted. Overall, it was a decent experience.
Interview questions [1]
Question 1
implementing K-means clustering from scratch and handling empty cluster edge cases
three rounds, each has coding + ml basic + resume related questions
understand all the details in resume is important, since might go very deep down the project you have worked on
The first round was mainly a CV walkthrough.
The second round focused in depth on one specific project.
Both rounds also included LeetCode medium-level problems.
The third round was with the hiring manager with both project and problems for their business.