TikTok interview notes, page 16 of 28

Large Enterprises

Most of these TikTok write-ups come from Data Scientists (111), then Software Engineers (102) and Product Managers (35). The most reported rounds are the technical phone screen (167), the product sense round (33), the system design round (25) and the behavioral / leadership round (21).

279 interview notes · updated Sep 2026

TikTok·Data Scientist·Technical Phone Screen

Jun 2026

TikTok data scientist interview with a product analytics case about diagnosing a metric drop post-release. Pretty standard scenario but the depth they expected was real.

The product dashboard shows a sudden drop in a key metric right after a new release. Walk me through how you'd investigate it and what analyses you'd run.

“I started with clarifying the metric which felt right, but I jumped too fast into segmentation before actually quantifying how bad the drop was.”

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TikTok·Software Engineer·Hiring Manager Screen

Jun 2026

Did my 3rd round with TikTok in San Jose and it was mostly behavioral. The experience felt a little off, lots of repeating myself, and I left unsure whether I actually answered what they were looking for.

Do you speak Chinese?
Can you walk me through your background and experience?

“Wasn't expecting this to be one of the first things out of their mouth.”

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TikTok·Machine Learning Engineer·Technical Phone Screen

Jun 2026

TikTok ML Engineer interview with a pretty gnarly tree problem that pushed into Morris traversal territory. The constraint of O(1) space and no recursion or explicit stack is where things got interesting.

You're given a binary search tree where exactly two nodes were swapped by mistake. Fix the tree to restore valid BST order without restructuring it. The catch: O(n) time, O(1) space, no recursion, no explicit stack. Walk through how you'd detect the swapped nodes and handle both adjacent and non-adjacent cases.

“This one took me a minute to even parse what they were asking.”

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TikTok·Software Engineer·Technical Phone Screen

Jun 2026

TikTok SWE interview with a linked list problem that looks manageable until you actually sit down to implement it. The group-reversal logic with the edge case on the final group is where things get tricky.

Given the head of a singly linked list, traverse it in contiguous groups of increasing size (1, 2, 3, ...). For each group, reverse it if its actual node count is even, and leave it alone if odd. The last group may be shorter than expected, so use its real length to decide. Return the modified list head.

“I spent way too long second-guessing the final group edge case.”

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TikTok·Data Scientist·Technical Phone Screen

Jun 2026

SQL-heavy data science interview at TikTok, four questions all centered on a food-delivery marketplace schema. The problems escalated from basic aggregation to window functions and quartile bucketing, which felt like a lot to get through in one sitting.

For each calendar month, what percentage of distinct customers placed more than 30 orders that month?
For each month, find the customer(s) with the highest order count among those who placed 30 or fewer orders. Then, as a follow-up, find the single customer with the most total orders across all months with no exclusion.
For a given restaurant, compute its monthly total sales in 2021 and the month-over-month change, showing only months that have a prior month to compare against. Follow-up: how would you extend this to all restaurants?
Each month, rank restaurants into four buckets by that month's total sales. Then compute the percentage of distinct customers who placed at least one order from a bottom-quartile restaurant in that month.

“Straightforward once you break it into two steps: count orders per customer per month, then aggregate at the month level.”

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TikTok·Product Manager·Onsite - Product Sense / Strategy

Jun 2026

PM interview at TikTok, product sense round focused entirely on game design. Two meaty questions back to back, no behavioral fluff, just straight into the deep end.

Design a new game for TikTok. Walk through your product vision, who you're building it for, the core gameplay loop, and what you'd ship first.
What actually keeps players coming back to a game over time, and how would you build that into your design from the start?

“I went broad too fast.”

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TikTok·Data Scientist·Technical Phone Screen

Jun 2026

TikTok Data Scientist SQL round, two-part question covering window-function-style aggregation and conditional counting. Pretty straightforward if you know your GROUP BY tricks, but the tie-breaker detail on the first part tripped me up a bit.

Given a products table with category, price, and discount columns, return the product with the highest discount in each category. If there's a tie on discount, pick the one with the lowest product_id.
Using a submissions table that tracks employer IDs and whether each submission is buggy or non-buggy, write a query to count both types per employer.

“I went straight for a subquery with MAX(discount) grouped by category, joined back to the original table.”

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TikTok·Software Engineer·Onsite - Multi Round

Jun 2026

Third round at TikTok, two project questions, fifteen minutes, then a rejection. The whole thing felt like a formality and left a pretty sour taste.

Walk me through your project work and the decisions you made.

“Two questions about my project, fifteen minutes total, and the guy said 'that's it from my end.' I didn't even feel like I had a chance to say anything meaningful.”

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TikTok·Software Engineer·Onsite - Product Sense / Strategy

Jun 2026

Interviewed for a bizops role at TikTok and got hit with a revenue growth case right away. Pretty open-ended stuff with no clean answer, which was either fun or stressful depending on your mood that day.

How would you approach doubling TikTok's revenue in the next year, and what share of that growth should come from existing advertisers versus bringing in new ones?

“The second part is what tripped me up.”

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TikTok·Product Manager·Onsite - Product Sense / Strategy

Jun 2026

Short PM screen at TikTok, basically just one competitive landscape question from what I can tell.

Who are TikTok's main competitors?

“Seems basic but I fumbled it a bit by just listing names without saying anything interesting.”

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