I applied through an employee referral. The process took 2 weeks. I interviewed at TikTok (San Jose, CA) in Sept 2025
Interview
Interviewed for a New Grad AI/ML back-end position. First round was standard CodeSignal. Second round was a 1-hour technical interview.
Despite the recruiter telling me to expect LC Med/Hard and ML theory questions, I was asked computer architecture questions. The rest of the interview was an LC Hard.
Interview questions [1]
Question 1
Explain how CPU scheduling and virtual memory work.
OA - 1 arrays Medium, 1 Trie Hard. I had 45 minutes to complete that. I was able to do the medium in about 15-20 minutes but I am not that great with trie ds so I was not able to finish.
Four Round Process
Phone Interview with Human Resources
Coding Round; 1 DSA Leetcode Medium Q
Coding Round: 2 DSA Leetcode Medium Q
Manager Round: System Design Q and behavioural Q
It took about four weeks from application to offer, longer than I initially expected. The initial phone screen was straightforward, covering my resume and some basic algorithms. Then came the technical rounds, which were challenging. One question on minimum window substrings had me diving into a sliding-window approach using pointers and hashmaps. Funny enough, I recognized it mid-round as something I’d practiced on PracHub just days before. After a final system design discussion, I received the offer and happily accepted.
Interview questions [1]
Question 1
Given two strings s and t, return the minimum window substring of s that contains every character of t including duplicates, or an empty string if no such window exists. Walk through the sliding-window approach using two pointers and a character-frequency hashmap, analyze the O(|s| + |t|) time complexity, and discuss how to adapt it when t contains characters not present in s or when s arrives as a stream that cannot be fully buffered.