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."
Calculate Probabilities for Mixed Reviewer Types
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Measure Billboard Campaign Effectiveness and Engagement Quantification
Measure Billboard Campaign Effectiveness and Engagement Quantification A consumer social platform places billboards in train stations to drive traffic...
Influence Decisions Without Direct Authority: Strategies and Outcomes
Influence Decisions Without Direct Authority This behavioral prompt asks about influencing cross-functional decisions without formal authority in a da...
Define Success Metrics and Experiment Plan for Product Development
Define Success Metrics and Experiment Plan for Product Development You are in a product-planning session for a new change to the core booking funnel i...
How to Analyze and Model Behavioral Data Effectively?
Analyze and Model Behavioral Data Effectively You receive a raw event-level behavioral dataset for a product funnel. The interviewer asks you to clean...
Improve Profile Completion Rate
Increasing LinkedIn Profile Completion Profile completeness affects members' visibility in search, job matches, recruiter outreach, and trust. Assume ...
Design Test Cases for UI Change: Ensuring Quality and Functionality
Mission-Aware QA Collaboration: UI and Backend Testing You are interviewing for a Data Scientist role that collaborates closely with QA engineers and ...
Analyze Global Engagement and Impressions with SQL Queries
impressions +---------+---------+----------+----------------+ | user_id | country | category | impression_cnt | +---------+---------+----------+------...
Design Experiment to Evaluate New Video-Ad Effectiveness
Design an Experiment to Evaluate New Video-Ad Effectiveness A large consumer app is considering a new video-ad format with changes to UI, creative ren...
Resolve Stakeholder Conflicts: Actions and Outcomes Explained
Behavioral Interview: Navigating Stakeholder Conflict You are a Data Scientist delivering a product or experiment with stakeholders such as Product, E...
Match payments to invoices by memo or amount
Scenario You are building a small reconciliation tool that matches payments to invoices. Data structures Assume you are given: - invoices: a list of i...
Combine noisy thermometers; compute random-walk correlations
Problem 1: Estimating a true temperature from noisy thermometers Assume the true (fixed) temperature is an unknown constant \(\theta\). 1a) One thermo...
Evaluate an email test with confounding
Evaluate an Email Test With Confounding A marketing team tested Email A and Email B across two cities, San Francisco and New York, over two weeks. The...
Compute win probability in coin-toss game
Two players, A and B, play the following game with a fair coin: - They toss the coin alternately: A tosses first, then B, then A, then B, and so on. -...
Explain forward contracts and options
In a finance-focused technical interview, you are asked to explain two basic derivative instruments: 1. What is a forward contract? 2. What is an opti...
Find kth missing integer and redundant operations
You are given two independent coding tasks. Task 1: K-th missing number You are given an integer array nums (not necessarily sorted) containing distin...
Find recommended friend pairs by shared songs
You work on a music app and want to recommend “friend” connections based on listening similarity. Assume the following tables (all timestamps are in U...
Reduce LLM hallucination and handle class imbalance
Answer the following applied ML/LLM questions. 1) LLM hallucination & token cost control You are building a chatbot over an internal knowledge base. 1...
Design an experiment to evaluate a new ads algorithm
You are a Product Analytics/Data Science partner for an ads ranking/recommendation team. Facebook has shipped (or plans to ship) a new ad recommendati...
How would you design Shop-ad ranking?
Suppose the previous experiment shows that, in some contexts, users are more likely to convert when shown an ad that leads to an in-app Shop rather th...