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."
Analyze Cancellation Change with Statistics
A/B change in cancellation rate (before vs after) Context: You are evaluating a small product tweak intended to reduce cancellations. Treat each trip ...
Derive uniform RNGs from limited or biased sources
Sampling Construction and Analysis: From rand5() to rand7(), General randM()→randN(), and Fairness from a Biased Source You have access to a uniform p...
Decide to ship a signup experiment
A/B Test Plan: Redesigned User Signup Flow Context and Data You are analyzing an A/B experiment for a redesigned user signup flow. The dataset include...
Design and evaluate a dasher bike rollout
Program Evaluation: Allow Car Dashers to Also Use Their Own Bikes/E-bikes Context DoorDash (DD) will relaunch an opt-in feature that lets existing car...
Measure Ads Manager effectiveness end-to-end
Measure TikTok Ads Manager's Effectiveness on Advertiser Success Context: You are evaluating new Ads Manager capabilities (e.g., workflow streamlining...
Interpret and validate regression with interactions
Modeling 7-day Retention with LPM and Logistic Regression Context You have user-level data with a binary outcome retained_7d (1 if the user is active ...
Redesign an executive dashboard for C-suite
Redesign a Spaghetti Chart into an Executive Dashboard Context You are handed a single slide for the C‑suite that shows a spaghetti chart of regional ...
Define success metrics and guardrails for B2B chat
Define a Success-Measurement Plan for a New EU B2C Chat Subscription You are launching a paid business-to-customer chat subscription in the EU. Design...
Communicate technical impact under skeptical stakeholders
Reframing a Multi‑Team Project for a Technical‑Only Hiring Manager Context You are a data scientist in a technical screen. You need to present a multi...
Decide launch of downranking suspected bad sellers
Experiment Design: Downranking Suspected Bad Sellers in Search Context - You are designing a decision framework and online experiment to test penalizi...
Compute 7-day rolling complaint/order ratio in SQL
SQL only. Given the schema and sample data below, write a single Postgres query (no procedural code) to compute a 7-day rolling complaint-to-order rat...
Handle PM Ambiguity and Drive Outcomes
Behavioral + Incident Response Interview Prompt Part A — Leadership Under Ambiguity Tell me about a time a PM dominated a discussion with ambiguous go...
Design a Cold-Start-Aware Recommender
System Design: Two-Stage Recommender for a New Content App Context You are designing recommendations for a new content app with sparse interactions an...
Design profit evaluation for loyalty program
Loyalty Program Incremental Profit Evaluation Plan Context A national grocery chain launched a free loyalty card on January 1. You have 18 months of h...
Choose the right test for proportions
A/B Test on Delivery Completion Rate (Binary Outcome) Context: You are evaluating an A/B test on a binary metric (delivered_bool). Treat each order as...
Design a quasi-experiment for FHFA policy
Causal Impact of FHFA's April 15, 2024 Multifamily Underwriting Tightening Context On April 15, 2024, FHFA tightened underwriting standards for multif...
Model session times and comments with exponential/Poisson
Session Duration Memoryless Assumption and Poisson Comment Counts Setup - We model user session end times with a constant hazard (memoryless) over tim...
Compute posterior for accurate-but-rare classifier
Bayes' Theorem: Interpreting Screening Model Predictions Context You are evaluating a binary screening model that flags "bad" users in a population. T...
Explain fit for Capital One BA
Behavioral Prompt: 2‑Minute Pitch for a Business Analyst Interview at Capital One Task Deliver a concise, 2‑minute response that covers: 1. Who you ar...
Explain life story, project leadership, and negotiation
Behavioral & Leadership — HR Screen (Data Scientist) In a single, structured answer, address all items below with specific dates, names, and quantifie...