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."
Build and evaluate bad-link classifier
You have 1,000 URLs labeled as bad or good and a much larger unlabeled pool, with bad links rare. Design features and train a logistic regression. Exp...
Write SQL for hashtag source and safety rates
Write SQL for the two tasks below. Assume the schema and sample data as given, and that “today” is 2025‑09‑01. Deduplicate exact duplicates by (date, ...
Profile and visualize an unfamiliar dataset
Task: Quickly Understand an Undocumented Events+Purchases CSV and Produce Executive-Ready Visuals Context You are handed a single CSV that mixes user ...
Design student–course data models and SQL
Scenario: Model a university domain with Students, Courses, Departments, Instructors, and Enrollments. Tasks: 1) OLTP ERD: Specify normalized tables w...
Clarify status, education, and multi-role strategy
HR Screen: Candidate Information and Minicase Readiness (Data Scientist) 1) U.S. Work Authorization Provide your current employment/visa status and wo...
Handle missing data and outliers robustly
Customer Churn Modeling: Preprocessing, Missingness, Outliers, and Evaluation Context You are building a binary churn model for a consumer subscriptio...
Count buggy vs non-buggy by employer
Count buggy vs non-buggy submissions for each employer_id, including employers with zero submissions. Return employer_id, buggy_count, non_buggy_count...
Choose alternatives when randomization fails
Causal Impact of an Autoloaded Feature Without Clean Randomization Context You need to estimate the causal effect of a new autoloaded feature that is ...
Design city home-price prediction system
End-to-End System Design: Predict Residential Property Sale Prices Context You are tasked with building a production-grade machine learning system to ...
Diagnose outliers and influence in linear regression
OLS Diagnostics: Outliers, Leverage, Influence, and Cook's Distance Context You are fitting an ordinary least squares (OLS) linear regression with an ...
Relate Y-on-X and X-on-Y coefficients
Relating Slopes When Reversing Simple Linear Regression Context You fit an ordinary least squares (OLS) simple linear regression with an intercept of ...
Derive lower bound for equicorrelation rho
Equicorrelation Matrix PSD Condition Setup Consider zero-mean, unit-variance random variables whose pairwise correlations are all equal to a common va...
Implement max profit with K transactions (DP)
Given an array prices[0..n-1] of daily stock prices and an integer k, implement a bottom-up dynamic program to compute the maximum achievable profit w...
Demonstrate cross-functional collaboration and influence
Behavioral Prompt — Cross-Functional Collaboration (STAR) Provide a specific example of cross-functional collaboration with a Product Manager (PM) and...
Lead a cross-team fraud incident response
Describe a specific time you led a high-severity ACH fraud incident from detection to resolution. Include: (1) the first on-call signal you saw, (2) t...
Write SQL/Python for ACH fraud analytics
As of today (2025-09-01), use the following schema and tiny samples to answer. Provide SQL for the SQL parts and Python for the Python part. Schema - ...
Build DiD dataset with SQL
Using the schema and sample data below, write SQL to build an individual-day panel suitable for staggered-adoption DiD of the shuttle’s effect on part...
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...