Tiktok Interview Questions
Practice the exact questions companies are asking right now.
Compare Random Forests and Boosted Trees: Bias, Variance, Speed
Scenario A product/data science team is deciding between Random Forests and Gradient-Boosted Decision Trees (e.g., XGBoost) for a new predictive task....
Tiktok DS Interview Questions
Scenario: You are provided with two tables: minute_streamed and minute_viewed. The minute_streamed table records each minute of streaming activity, wh...
Design low-latency large-scale hotel booking system
You are asked to design the backend for a large-scale hotel booking system that runs behind a very high-traffic consumer app (think a TikTok-like app ...
Design A/B Test for Cost-Per-Conversion Efficiency Analysis
Multi-Arm A/B Test: Comparing Cost-Per-Conversion Across Channels Scenario You need to compare four new acquisition channels—YouTube ads, Google Searc...
Diagnose metric drop in Ads Manager
Investigate a 15% Drop in Ad-Creation Completion Rate Context On 2025-06-10, your Ads Manager dashboard shows a 15% relative decrease in the ad-creati...
Solve message splitting and board crushing
Question LeetCode 2468. Split Message Based on Limit – Given a message string and a per-line width, split it into parts adding the suffix "<i/n>" (e.g...
Design a high-concurrency ticketing system
Design a High-Concurrency Ticketing/Flash-Sale System (Limited Seats) Context You are designing the backend for a limited-seat flash sale (e.g., conce...
Resolve Stakeholder Conflicts: Actions and Outcomes Explained
Behavioral & Leadership: Navigating Stakeholder Conflict (Data Scientist) Context You are a Data Scientist delivering a product/experiment with multip...
Prove conversion ads value via incrementality
Measuring Incremental Lift of Conversion-Optimized Ads Context An e-commerce advertiser is running conversion-optimized ads and requests rigorous proo...
Explain SRE architecture and troubleshooting scenarios
Kubernetes, Reliability, and Data Store Concepts (Technical Screen) Context: Assume you operate a high-scale, latency-sensitive microservices platform...
Solve intervals and distinct islands
Question LeetCode 56. Merge Intervals LeetCode 694. Number of Distinct Islands https://leetcode.com/problems/merge-intervals/description/ https://leet...
Compute CTR drop with exclusions
Assume today = 2025-09-01. Using ad delivery logs, find advertisers whose CTR in the last 7 days (2025-08-25 to 2025-08-31) dropped by at least 20% re...
Interpret and validate regression with interactions
Modeling 7-day Retention with LPM and Logistic Regression Context You have user-level data with a binary outcome retained_7d (1 if the user is active ...
Explain your most impactful project trade-offs
Behavioral Prompt: 2–3 Minute Project Walkthrough (Data Scientist, Technical Screen) Deliver a concise, 2–3 minute walkthrough of the single most impa...
Write SQL for last-7-day metrics without windows
Assume today is 2025-09-01. Use ANSI SQL only and do not use window functions. You may use subqueries, GROUP BY, HAVING, and JOINs. Schema and small s...
Choose linear regression or decision tree appropriately
Choose Between Linear Regression and a Decision Tree Under a Hinge and Interaction DGP Context You have 100,000 i.i.d. observations with features x1 (...
Optimize threshold using confusion matrix and costs
Calibrated Classifier on an Imbalanced Dataset (1% positives) You have a perfectly calibrated binary classifier evaluated on 10,000 held-out examples....
Derive L1 vs L2 effects with correlation
Multicollinearity: Ridge vs LASSO vs Elastic Net Setup - Two standardized predictors x1 and x2 with corr(x1, x2) = 0.99. - X'X = [[100, 99], [99, 100]...
Investigating Correlation Between Ad Visits and Reports
Scenario You are on the analytics team at a large social media platform. A positive correlation has been observed between the number of page visits to...
Flatten object & Promise.all
Question Given a nested JavaScript object, write a function to flatten it so that nested keys are converted to a single-level path (e.g., {a:{b:1}} ->...