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."
Diagnose Causes of High Out-of-Stock Rate in Groceries
Diagnose Causes of High Out-of-Stock Rate in Groceries Product and Operations Case: Grocery OOS, Delivery Radius, and Free Delivery Context You are a ...
Design a Controlled TV-Advertising Experiment for Sign-Ups
Design a Controlled TV-Advertising Experiment for Sign-Ups Controlled TV Advertising Experiment: Incremental Website Sign-ups Context You are asked to...
Design Machine Learning Model for Facebook Groups Post Ranking
Design Machine Learning Model for Facebook Groups Post Ranking ML System Design: Ranking Facebook Groups Posts in News Feed Scenario You are designing...
Find Smallest Missing Positive Integer in O(n) Time
Scenario LeetCode-style algorithm phone interview Question Implement a function that returns the smallest missing positive integer in an unsorted inte...
Describe Handling Unexpected Feedback and Actions Taken
Describe Handling Unexpected Feedback and Actions Taken Behavioral: Resilience After Unexpected Negative Feedback or Rejection Context You are in an o...
Optimize Travel Costs and Generate Rotational Symmetric Numbers
Scenario You are building a travel-search engine that must 1) show customers the cheapest round-trip they can book if departure and return prices vary...
Determine Key Metrics and Design A/B Test for Ad Ranking
Determine Key Metrics and Design A/B Test for Ad Ranking Experiment Design: Replacing Rule-Based Ad Ranking with a Recommender Context You are launchi...
Ensure Fairness Beyond Gender Parity in Lending Practices
Ensure Fairness Beyond Gender Parity in Lending Practices Fair Lending Behavioral Interview Prompt Scenario You are discussing fair lending practices ...
Determine Optimal Marketing Budget Allocation for Maximum Profit
Determine Optimal Marketing Budget Allocation for Maximum Profit Budget Allocation Across Acquisition Channels Context You are given an Excel sheet wi...
Train GradientBoostingClassifier with 5-Fold Cross-Validation
Train GradientBoostingClassifier with 5-Fold Cross-Validation Final Model Training: GradientBoostingClassifier with 5-Fold CV Context Assume the noteb...
Detect Overfitting or Underfitting in Logistic Regression Models
Detect Overfitting or Underfitting in Logistic Regression Models Logistic Regression Bias–Variance in High‑Dimensional Ads Prediction Scenario You are...
Diagnose Bias–Variance Trade-off in Supervised Learning
Diagnose Bias–Variance Trade-off in Supervised Learning Supervised Learning Review (Customer-Facing Ranking Context) You are designing and evaluating ...
Analyze Change in App Metrics and Feature Impact
Analyze Change in App Metrics and Feature Impact Scenario A consumer app has either launched a new feature or observed a sudden change in a key metric...
Describe Solving Complex Project Challenges in Detail
Describe Solving Complex Project Challenges in Detail Behavioral: Ownership and Problem-Solving (Data Scientist Phone Screen) Prompt Describe the most...
Design an Experiment to Evaluate New Recommendation Model
Design an Experiment to Evaluate New Recommendation Model Experiment Design: New Ads Ranking Model vs. Current System Context You are evaluating a new...
Investigate Declining ROI and Propose Effective Solutions
Investigate Declining ROI and Propose Effective Solutions E-commerce Ads Effectiveness and Diagnostics (Analytics & Experimentation) Context You are a...
Describe Your Professional Growth and Key Learning Experiences
Describe Your Professional Growth and Key Learning Experiences Behavioral Interview — Life Story: Growth and Readiness Scenario A 60-minute “life stor...
Determine Factors Influencing Airline Flight Delays Statistically
Determine Factors Influencing Airline Flight Delays Statistically Determine Drivers of Airline Flight Delays Context You are analyzing a flight-level ...
Count Word Frequency and Print Top Three Words
Scenario First-round Python coding screening Question Using only basic Python, write a function that receives a list of strings and returns a dictiona...
Design Experiment to Measure Airport Surge-Pricing Impact
Design Experiment to Measure Airport Surge-Pricing Impact Experiment Design: Causal Impact of Airport Surge-Pricing Push Notifications on Driver Suppl...