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."
Implement R dplyr simulation and left join
Using R and dplyr, run a simulation and a join. Data: prices item_id | price_usd 1 | 10.00 2 | 20.00 3 | 30.00 4 | 40.00 catalog item_id | category 1 ...
Diagnose a sudden metric spike or drop
Investigate a 3-Day Jump in Checkout Conversion Rate (CCR) Context On 2025-06-12, the daily Checkout Conversion Rate (CCR) increased from 3.2% to 4.5%...
Compute two conditional probability scenarios
Probability — Two-Part Question Solve both parts. Show formulas and provide final numeric values. Part A — Coin Type Given HHH - A box has 5 coins: 3 ...
Analyze daily comments distribution and sampling
Daily Comments per Active User: Sampling and Inference You have, for a given day d, the count of comments made by each active user. Let there be m act...
Select interest thresholds under skewness and cost
Profit-Optimal Threshold Selection from an Interest Score You have a per-user interest_score s ∈ [0, 1] for a new feature. The score distribution appe...
Diagnose sustained drop in executed trades
Brokerage Analytics Troubleshooting: Trades Per Active User Down 22% Context You are the analyst for a brokerage product that spans onboarding through...
Compute binary-tree diameter via return-only DFS
Given the root of a binary tree, compute its diameter defined as the number of edges on the longest path between any two nodes. Implement a DFS that r...
Detect and quantify wash trading
Detecting and Quantifying Wash Trading on a Centralized Exchange Context You are designing an analytics approach for a centralized exchange to detect ...
Summarize your background concisely
Behavioral Prompt: 60–90 Second Career Walkthrough (Data Scientist, HR Screen) Context You are interviewing for a Data Scientist role in a consumer-te...
Define market-only rider experience metrics
Market-only Rider Experience Metrics and Market Balance Index (MBI) You are designing a metric suite for a rides marketplace where "rider experience" ...
Demonstrate JD skills with quantified outcomes
Data Scientist HR Screen: Map a JD Skill to Your Resume Project Pick one skill explicitly highlighted in the job description and one project from your...
Design analytics and experiment for group video calls
Evaluate and Launch Group Video Calls — Product Analytics Plan Context: You are evaluating a new Group Video Call feature in a large-scale consumer me...
Root-cause an incident and drive consensus
Root-Cause Plan: Sudden Drop in Voice Checkout Conversion (Alexa Shopping) You are informed that the "voice checkout conversion" KPI for Alexa Shoppin...
Demonstrate Leadership in Ambiguous Analytics Projects
Behavioral & Leadership: End-to-End Analytics Project Under Ambiguity and Time Pressure Context You are a Data Scientist interviewing for a technical ...
Write SQL and Pandas for Uber Trips
Assume 'today' = 2025-09-01. You are given the following schema and small ASCII samples. Tables - riders(rider_id, name, signup_date) - drivers(driver...
Design an A/B test for ML model launch
Feed Ranker A/B Test Design and Powering You are replacing the current ranker with a new model in a feed. Baseline CTR is 2.0%. You expect a +5% relat...
Evaluate channels and allocate budget
Marketing Analytics Case: Funnel, Attribution, Budget Optimization, and Incrementality You are given a daily-by-channel dataset with the following col...
Analyze aggregator lender page flows
Loan Comparison Page: Instrumentation, Metrics, Insights, Experiment, and Cannibalization Context You own a loan comparison page (similar to NerdWalle...
Control confounding in observational ad lift
Estimating the ATE of Ad Exposure on Conversions (Observational Setup) You cannot randomize ad exposure. Users differ in age, education, income, and o...
Design email to avoid Promotions without online tests
Offline Design of a Transactional Email to Minimize Promotions/Spam Classification Context You must finalize the design of a single in‑game transactio...