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 Business Decline Using Key Data Metrics
Diagnose a Sudden Business Downturn Using Data Context You are the data scientist supporting a large consumer marketplace. Leadership reports a sudden...
Compute Customer Spend and Engineer Features for 2023
transactions +-----------+-------------+--------+------------+--------------+ | tran_id | customer_id | amount | tran_date | merchant_cat | +------...
Generate Daily Unique User Views for Each Shop
shop_views +---------+---------+---------------------+ | user_id | shop_id | view_time | +---------+---------+---------------------+ | 101 ...
Calculate Week-over-Week Revenue Change Using SQL
transactions +----+---------+---------+------------+ | id | user_id | revenue | order_date | +----+---------+---------+------------+ | 1 | 101 | ...
Evaluate Fake-Account Classifier with Precision and Recall Metrics
Evaluating a Fake-Account Classifier in Production Scenario You have trained a model that flags fake accounts. Leadership wants clear, defensible evid...
Evaluate Success of 'Similar Listings' Notification Feature
Marketplace Analytics Case: "Similar Listings You May Like" Notifications Context You work on a marketplace where buyers browse and purchase listings....
Verify Machine-Learning Fundamentals for E-commerce Recommendation Platform
Rapid ML Fundamentals Check — Recommender Systems Context You are interviewing for a data-science role on an e‑commerce recommendation platform. The h...
Measure Late Deliveries and Identify Top Delayed Restaurants
orders +----------+---------+--------------+---------------------+-------------------------+-----------------------+ | order_id | user_id | restaurant...
Evaluate Cohort Posting Patterns Using Metrics and Tests
Assessing Whether Cohorts Have the Same or Different Posting Patterns Context You have multiple creator cohorts (e.g., by signup month or first-post w...
Analyze Posting Behavior by Cohort and Date
creator_post +------------+---------+------+ | post_date | user_id | post | +------------+---------+------+ | 2023-01-01 | 111 | 1 | | 2023-01...
Identify Duplicate Posts by User and Date
posts +---------+---------+---------------------+---------------+ | post_id | user_id | created_at | content | +---------+---------+---...
Calculate 95% Bootstrap Confidence Interval for Order Values
Scenario An e-commerce firm wants a 95% confidence interval for the average order value but only has a single historical sample of order amounts. Ques...
Calculate Weekly, Monthly Hours Watched by Premium Users
watch_events +-----------+----------+----------------+-----------------------+----------------+ | user_id | video_id | watched_minutes| watched_at ...
Estimate Super Bowl QR Code Scan Rate Using Historical Data
Estimating QR Scan and Sign-up Conversion for a Super Bowl TV Ad Scenario A Super Bowl TV ad prominently features a QR code and a clear call-to-action...
Retrieve First Active and Last Inactive Dates per User
Given a table activity that tracks user activities, write a SQL query to retrieve the first active date and last inactive date for each user. Table Sc...
Design Sampling Strategy to Estimate Fake News Proportion
Estimating Fake News Prevalence and Impact on Facebook Context Management is concerned about the volume and impact of fake news on the platform. You a...
Determine Metrics for Evaluating Homepage Recommendation Carousel
Experiment Evaluation: Homepage Recommendation Carousel Scenario A product team has shipped an A/B test for a new recommendation carousel placed on th...
Answer behavioral prompts for quant internship
Behavioral and Leadership Prompts for a Data Scientist Take‑home Context You are applying for a Data Scientist role and are asked to respond to behavi...
Write SQL for rolling default rates
Write a SQL query to compute 12‑month rolling default rates by customer segment. Assume table loans(month DATE, segment TEXT, defaults INT, accounts I...
Diagnose Discrepancy in A/B Test Conversion Rate Results
A/B Test Design: Personalized Marketing Emails and Conversion Lift Scenario An e-commerce firm wants to send personalized marketing emails to increase...