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."
Solve relative-truth cat puzzle
Logic Puzzle: Directed Truth/Lie Rule and Cat Counts Three people (Asta, Bronya, Clara) each own a different number of cats (positive integers). When ...
Solve animals-and-legs count
Barn Legs Puzzle (Linear Equations) Convert the word problem into a small system of linear equations and solve. You have a barn with three types of an...
Compute delivery order via BFS
A city road network is an unweighted, undirected graph G(V, E) with a depot node s and D delivery requests located at nodes r1..rD, each with an integ...
Investigate Harassment Surge and Mitigation
Question You work on content integrity. Your monthly moderation analysis shows that the Harassment violation type increased sharply in the most recent...
Measure impact of ads-manager automation feature
Context An Ads Manager product has new automation features (e.g., auto-bidding, auto-budgeting, auto-creative suggestions). You need to measure the fe...
Traverse org chart level by level
Problem You are given an organization chart as manager relationships. Each employee is represented by: - employee_id (string/int) - manager_id (string...
Answer common DS behavioral screen questions
You are interviewing for a Data Science internship. Answer the following behavioral questions. 1. Introduce yourself (30–60 seconds). 2. Project deep ...
Prepare responses to UBS behavioral and stock-pitch prompts
Prompt set (video / HireVue-style) You will answer the following prompts, typically under tight time limits (e.g., ~1–2 minutes per question). Provide...
Optimize interval-scoring strategy
Five-Round Interval-Estimation Game: Optimal Intervals and Risk Allocation You play five independent rounds. In round i, an unknown numeric answer A i...
Walk through a data pipeline project
Describe a data pipeline project you built or owned end-to-end. In your answer, cover: - The business problem and downstream consumers (dashboards, mo...
Describe algorithm to find function maximum
Consider a real-valued, differentiable function f(x) defined on R (or more generally on R^n). You have access to an oracle that, for any input x, can ...
Estimate Volatility from Gaussian and Brownian Samples
You are given two statistical estimation problems. 1. Let X_1, ..., X_100 be independent samples from N(0, sigma^2), where the mean is known to be 0 a...
Showcase initiative and collaboration examples
Behavioral & Technical Prompts (Data Scientist — Take-Home / Onsite) This is a multi-part behavioral interview for a Data Scientist role on a financia...
Identify Overlapping Sessions and Optimize Coverage
Scenario During the technical screen, candidates must implement interval algorithms used in fraud-detection pipelines to reconcile overlapping user ac...
Calculate Expected Flips for Two Heads Coin Toss
Scenario Experian DataLabs online assessment – core probability section. Several short probability problems are asked back to back, covering coin-flip...
Explain Propensity Score Matching and Assess Covariate Balance
Propensity Score Matching (PSM) Context You have observational data with a binary treatment (T ∈ {0,1}), an outcome (Y), and a set of pre-treatment co...
Explain K-Fold Cross-Validation and Its Trade-Offs
Technical Phone Screen: Cross-Validation Task You are interviewing for a Data Scientist role. Explain and reason about k-fold cross-validation. Questi...
Calculate Break-Even Point and Profit Impact Analysis
Break-even and Profit Sensitivity for a Restaurant Context A restaurant has fixed monthly costs (rent, salaries) and a variable cost per customer (foo...
Explain P-Value Reporting and Bootstrap for Coefficient Estimation
Scenario Technical screen — statistical inference checks after regression. Questions 1) You observe a regression output where a coefficient's p-value ...
Design A/B Test for Marketing Campaign Impact Evaluation
Scenario A credit card issuer is testing a marketing campaign that waives the first-year annual fee. You need to design an A/B test to measure increme...