TikTok OA Report | Research Assistant Internship | Dec 2025
Summary
I recently took the TikTok OA for a Research Scientist internship. It was proctored on CodeSignal, consisting of 4 problems with 70 minutes time limit.
Full Experience
I recently took the TikTok OA for a Research Scientist internship. It was proctored on CodeSignal, consisting of 4 problems with 70 minutes time limit.
- Q1 (Easy): Combinatorics/Counting. Solved in 2 mins.
- Q2 (Easy): Simulation. Had a tricky edge case; took about 15 mins.
- Q3 (Medium/Hard): Complex simulation and state management. Very time-consuming.
- Q4 (Medium): String counting/permutations.
I finished the first two with 50 minutes remaining. After reading Q3, I skipped to Q4 to secure points. I hit a snag on Q4 with hidden test cases and ended with 240/300 on that task. I wrote the code for the Q3 but unfortunately, I ran out of time to pass any cases.
I got a total of 460/600 and am still waiting for their response!
Interview Questions (4)
A problem involving combinatorics or counting tasks.
A simulation problem with a tricky edge case.
A complex simulation problem requiring careful state management.
A problem involving string counting or permutations.