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."
Demonstrate ownership beyond responsibilities
Describe a time you proactively took on work outside your defined responsibility to deliver a measurable business outcome. Include: 1) context, stakes...
Evaluate a government-buyer energy investment
You are the CEO of Energy One, shifting from fossil fuels into renewables (nuclear, solar, hydro, biomass-from-corn). Build a rigorous decision framew...
Build and evaluate a full ML pipeline
You must predict both (1) probability that a user will spend >$0 in the next 7 days (classification) and (2) expected spend in the next 7 days (regres...
Write SQL/Python for messy event data
Using the schema and sample data below, write: (1) a single SQL query to compute daily metrics for the local date 2025-09-01 in America/Los_Angeles, a...
Identify non-table data for feature demand
Evaluate Demand for a New "Group Call" Feature Using Non-Table Data and Experiments Context You are a data scientist evaluating whether to invest in a...
Write SQL to analyze group-call concurrency
You are given call data and must compute group-call metrics. Schema (timestamps are UTC): Tables: - calls(call_id INT PRIMARY KEY, host_user_id INT, s...
Define and apply Gmail user segments
Question Gmail wants to create actionable user segments to drive both product improvements and marketing/lifecycle outcomes. Propose a segmentation sc...
Infer causal impact without an A/B test
Evaluate Impact of a Shipped Version on Disconnections (No A/B Holdout) Context A new client version was shipped system-wide with the goal of reducing...
Predict and act on contract renewal risk
Predicting Enterprise Contract Renewal After a Quality Incident Context A video-conferencing provider experienced a spike in call disconnects. You nee...
Quantify and optimize team-match funnel
Team-Matching Funnel: Metrics, Targets, and a 14-Day Experiment Plan Context You are designing analytics for a recruiting "team-matching" funnel that ...
Design and evaluate P2P payments in messaging
P2P Payments in a Large Messaging App — Design, Measurement, and Risk Plan You are a data scientist at an at-scale messaging platform evaluating a Ven...
Choose and compute recommender evaluation metrics
Restaurant Recommender: Offline Evaluation and Modeling Context: You are scoring p(y=1|x) with logistic regression to predict if a user will engage wi...
Compute posterior spam risk from flags
A binary classifier flags spammy requesters. Last week the base rate of spam among all requesters was 12%. The classifier has true positive rate (TPR)...
Build SQL pivot with lookups and currency conversion
You are given the following schema and sample data. Use SQL (or Python with SQL-like transforms) to answer the tasks below. Treat amounts as gross rev...
Estimate sales impact from reviews causally
Your PM asks: Do better product reviews cause higher sales, or do higher sales lead to more reviews? Design an analysis to estimate the causal effect ...
Compute p-values, probabilities, and regularization choices
Answer all parts. A) Hand‑compute a two‑sided p‑value comparing two means using Welch’s t‑test. Sample A: n1=20, mean1=5.2, sd1=1.1. Sample B: n2=24, ...
Measure causal impact of YouTube ads
Estimate the incremental effect of a 6‑week YouTube campaign on weekly online sales. - Explain why naive OLS of sales on ad spend is biased; list at l...
Replace legacy ads model safely
Facebook Ads Ranking Replacement: M0 to M1 You are asked to replace a legacy ads ranking model (M0) with a new model (M1) in a large-scale feed ads sy...
Characterize metric distribution and quantiles
KPI Analysis: Per-Video Watch Time (seconds) You are evaluating a pilot dataset for the KPI "per‑video watch time" (in seconds). The dataset (n = 20) ...
Define and compute shop visibility in SQL
You own the 'shop visibility' KPI for a marketplace. Define a precise metric and write SQL to compute it over the last 7 days (use today = 2025-09-01,...