Data Scientist Interview Questions
Practice 2,964 real Data Scientist interview questions for 2026. Data Scientist interview questions drawn from Meta, Capital One, Amazon, Google, TikTok and similar employers — real questions from actual interviews with detailed solutions — designed to accelerate your interview preparation for product analytics, ML and production data roles. This collection emphasizes the practical skills interviewers test: SQL and data manipulation, experiment design and A/B testing, statistical reasoning, Python coding for data problems, model evaluation and feature engineering, plus machine-learning system tradeoffs and metric design. What’s distinctive about modern data-science loops is the blend of product thinking and reproducible ML: expect hands-on SQL tasks and funnel analysis in screens, deeper experiment-design and causality questions in mid rounds, and coding or modeling challenges plus ML-system discussions in senior loops. Interviewers evaluate problem framing, statistical rigor, and how you communicate decisions to product partners. To prepare, prioritize daily SQL practice (CTEs, window functions), refresh hypothesis-testing and power calculations, rehearse concise metric-driven narratives, and build a few end-to-end model or experiment stories you can explain clearly under time pressure.

"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"

"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"

"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."

"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."

"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."

"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."

"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."

"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."

"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."

"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."

"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."

"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."

"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."

"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Evaluating Instagram’s one‑tap account switcher
Instagram Account Switcher: Identity Resolution, Behavior, and Risk Assessment Context Product teams shipped an in‑app, one‑tap account switcher to he...
Implement Data Structure for Top-K Elements in Streams
Scenario Analytics feature that must constantly report the K largest numbers seen so far. Question Implement a data structure that ingests a stream of...
Diagnose Discrepancy in A/B Test Conversion Rate Results
A/B Test Design: Personalized Marketing Emails and Conversion Lift Scenario An e-commerce firm wants to send personalized marketing emails to increase...
Influence Cross-Functional Teams Without Formal Authority
Scenario Snapchat Data Scientist onsite, behavioral and leadership focus. A cross-functional product launch (PM, Engineering, Design, and a partner pl...
Remove Duplicates While Preserving Order in List
Scenario A data pipeline receives an unordered list of IDs containing duplicates; downstream components require a duplicate-free list while preserving...
Optimize Job Routing in Parallel Machine Scheduling
Scenario In the Production Factory game, jobs with varying processing times arrive and must be routed through two parallel machines to minimize total ...
Build Classifier: Evaluate with AUROC for Imbalanced Data
Detecting Dead Links: Build and Evaluate a Classifier Scenario You have a dataset of 1,000 URLs labeled as good (alive) or bad (dead). The classes are...
Analyze DoorDash Orders: High-Frequency Customers, Top Spenders, MoM Sales & Bottom-Percentile Reach
orders +-------------+-------------+---------------+---------------------+ | delivery_id | customer_id | restaurant_id | order_place_time | +------...
Describe Your Proudest Graduate-Level Achievement and Its Impact
Behavioral Prompt: Graduate Coursework and Research Highlights Context You are in a data scientist technical/phone screen. The interviewer wants a con...
Build Accurate Energy Consumption Prediction Model for Utilities
Predicting Daily Energy Consumption: End-to-End Regression to Production Context You need to build and productionize a supervised regression model tha...
Evaluate the Health of Facebook Groups
Group Health Metrics and Experiment Design for Threaded Comments Context You are a Data Scientist working on a platform with Groups that range from sm...
Design Efficient Multi-Level Access Control System
Scenario Multi-level access control lists (country → city) must be queried quickly. Question Design and implement a permission system where each geogr...
Handle Missing Values and Outliers in Machine Learning
Technical Screening: Model Development Discussion Context You are building classification and regression models on tabular business data with missing ...
Predict Impact of 'Online Indicator' Feature
LinkedIn Messaging: Online Presence Indicator — Analytics Design Context LinkedIn plans to display an online presence indicator (for example, a green ...
Explore Subscription Patterns and Status Transitions with SQL/Pandas
subscriptions +-----------------+---------+-------------+ | subscription_id | status | status_date | +-----------------+---------+-------------+ | 10...
Design Data Structure for Sparse Matrices Operations
Scenario Analytics engine stores extremely sparse numeric matrices. Question Design a data structure to store two sparse matrices and implement print(...
Identify Top Contributors by Recent Post Count
posts +----+---------+---------------------+ | id | user_id | created_at | +----+---------+---------------------+ | 1 | 101 | 2023-09-01...
Clean and Aggregate Transactions for Finance Dashboard
transactions id | user_id | amount | timestamp | category 1 | 1001 | 19.99 | 2023-01-01 09:00:00 | grocery 2 | 1001 | 5.50 | 2023...
Evaluate Recommendation Feature with Historical Data Analysis
Offline Evaluation of a New Recommendation Feature Scenario You need to estimate the business value of a new recommendation-system feature using only ...
Improve TikTok's Algorithm for Diverse Content Discovery
Product Feedback and Experimentation Case Context You are a frequent TikTok user interviewing for a Data Scientist (Analytics & Experimentation) role....