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."
Design success and guardrail metrics
You are launching a new recommendation module on a content platform. Design a metrics framework and an experiment plan. A) Define one primary success ...
Compute posterior and predictive coin probabilities
Bayesian coin: posterior, prediction, and stopping-time expectation Context - You have two coins and will use the same coin for all flips: - Fair co...
Prove causality for trading metric drop
Goal You need to separate market-driven fluctuations from a product-caused decline in executed_trades per active user around a known release on 2025-0...
Explain handling very large datasets
Describe a project where you ingested and processed a dataset of at least 500 million rows or 1 TB end-to-end. Detail storage formats and partitioning...
Implement sqrt with Newton vs binary search
Implement numerically robust square-root routines and analyze convergence Task 1 — sqrt_newton(x, tol=1e-12) Implement a Python function that returns ...
Diagnose LA completed-order drop and design experiment
LA Dinner-Period Orders Down 12% WoW: Diagnose and Validate Root Cause Context You are analyzing a weekly decline in a two-sided delivery marketplace....
Navigate an ambiguous take-home assessment
Behavioral Case: Executing a 4–6 Hour Take‑Home Data Science Assignment Context You are a candidate for a Data Scientist role. You receive a one‑week ...
Compute and Rank by Jaccard Similarity
Implement two functions: (1) jaccard_similarity(s1, s2) that tokenizes by splitting on any non-alphanumeric character, lowercases, treats tokens as se...
Segment 500k users into three groups
Churn-Risk Segmentation to Maximize Expected 90-Day Revenue You must segment 500,000 users into three contiguous groups along a churn-risk score, orde...
Design an ETA experiment under interference
Experiment Design: Estimating Causal Impact of a New Rider ETA Model in a Two-Sided Marketplace Context You are testing a new rider ETA model that cha...
Choose estimators for panel rent regressions
Panel Rent–Vacancy Elasticity and Inference: Design, SEs, and Time-Series Diagnostics Context You have a monthly property-level panel from 2010-01 to ...
Compute current annual profit
Loyalty Program Profitability Calculation A loyalty program has 2,000,000 customers. Revenue per customer (per year): - Annual membership fee: $50 - C...
Calculate CI and Test Correlation Under Normality
Inference on a Mean, Significance of a Correlation, and a Normal Quantile Assume standard parametric conditions (normality as stated). Show formulas, ...
Build and evaluate an order prediction model
Predict 7-Day Order Completion from First Session You are building a binary classifier to predict whether a guest will complete an order within 7 days...
Build DID panel and compute effects in SQL
Using the schema and toy data below, write SQL to construct a user-week panel and compute a clean pre/post DID dataset for first reminder exposure. Re...
Influence policy with BI deliverables
BI/Fraud Stakeholder Case: Drive an Account Takeover (ATO) Policy Change in 90 Days You join the Chicago Fraud team as a Decision Scientist. The hirin...
Recover causal effect without a control group
Post-hoc Causal Estimation After a Failed A/B Rollout Context An intern accidentally shipped a feature to 100% of eligible users for 5 consecutive day...
Estimate impact of global launch without holdout
Causal Lift Plan After a Global Launch Without a Holdout Background A new product feature was launched globally on 2025-05-10, with no control or hold...
Reflect on a failed decision and redo it
Behavioral & Leadership (Data Scientist Onsite) Prompt: High-Stakes Decision That Turned Out Wrong Describe one specific decision you owned that mater...
Compute incremental profit, breakeven, and revenue sensitivity
Question You are evaluating whether to add a vegan burger line in Year 1. Use the following assumptions (m = million): - Fixed training cost: $60m/yea...