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."
Evaluate impact without randomized experiments
Estimating a Promotion's Causal Effect Without an Experiment Context You need to estimate the causal impact of a marketing promotion on engagement (e....
Analyze results and large p-values correctly
Experiment Analysis Plan: User-Level ITT with Robust Inference, Variance Reduction, Ratios, Skew, Non-Compliance, and Decision Framework Context You r...
Handle sales pressure with analytical integrity
Interview Scenario: Call Volume vs. Win Rate — Causation vs. Correlation You support Sales as a data scientist. Leadership observed a positive correla...
Diagnose sales correlations without claiming causality
Correlation-Focused Analysis: Outreach Channels vs. Deal Win Rate You support a sales team and are asked to find which outreach channels correlate wit...
Audit and onboard unfamiliar datasets safely
You inherit unfamiliar hotel search data with sparse documentation. Provide a concrete, ordered checklist to: a) discover tables/columns and verify pr...
Design SQL/Pandas aggregations on retail schema
Using the schema and sample data below, answer both parts. Assume today is 2025-09-01. Use standard SQL (e.g., PostgreSQL) and idiomatic pandas withou...
Design a robust email A/B test
A/B Test Design: New Email Subject Line for Weekly Campaign You manage a weekly email campaign to 10 million users. Baseline unique click-through rate...
Write monthly new-vs-returning requests SQL
Given the schema and sample data below, write a single PostgreSQL query (no dynamic SQL) that returns, for every calendar month present in requests, t...
Write complex joins and window functions
You are given a simplified Thumbtack-like marketplace schema in PostgreSQL. Assume UTC timestamps and weeks start on Monday. Treat "today" as 2025-09-...
Evaluate fraud classifier with cost-sensitive metrics
Binary Fraud Classifier: Metrics, Thresholding, Calibration, and Online Evaluation You inherit a binary fraud classifier used to decide whether to blo...
Derive no-click probability and sketch implications
Click Probability Across Repeated Impressions Context: We show A impressions of the same item to a user. Unless otherwise stated, each impression is a...
Compute weighted response rates by job category
You are given a CSV with one row per job posting and the following columns: job_id, job_category, invitations_sent (integer >= 0), provider_responses ...
Label game performance by margin
Given a games DataFrame (or R data.frame) with columns: team_id, opponent_team_id, team_score, opponent_team_score, write code to: (1) Define a functi...
Find 2023 NCAA championship winner
You are given two tables. Schema: team(team_id INT PRIMARY KEY, team_name TEXT); game(game_id INT PRIMARY KEY, team_id INT, opponent_team_id INT, date...
Clean, split, merge, and aggregate with pandas
Given two CSVs, use pandas to clean, split strings, merge, and aggregate. drivers.csv driver_id,name,signup_city D1,Jane Doe,SF D2,Mark S,NYC D3,A...
Write SQL for fares and age-band counts
You have two tables. Schema: - drivers(driver_id VARCHAR PRIMARY KEY, name VARCHAR, date_of_birth DATE) - trips(trip_id VARCHAR PRIMARY KEY, driver_id...
Estimate Super Bowl QR-driven registrations
Estimating Completed Registrations from a Super Bowl QR-Code Ad Context You are asked to estimate how many users complete registration from a single 3...
Compute browsing metrics in Python from logs
Given event logs, write idiomatic Pandas to compute segment-level metrics and a funnel. Data schema: events(event_id, ts_utc, guest_id, device in {des...
Design an experiment with marketplace network effects
Causal Experiment Design for a Two‑Sided Marketplace with Interference You are designing a causal experiment for a new networked product in a two‑side...
Design robust metrics for a feature launch
A/B Test Metrics and Guardrails for Quick Reply (1-week) Context You are adding a Quick Reply feature (suggested reply chips in the DM composer) to a ...