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."
List Departments with Student Counts Including Zero
Students +----+--------+---------+ | id | name | dept_id | +----+--------+---------+ | 1 | Alice | 1 | | 2 | Bob | 2 | | 3 | Caro...
Determine Facebook's Restaurant Recommendation Viability Using Data
Product Case: Restaurant Recommendations on Facebook Scenario Facebook is considering launching a restaurant-recommendation feature (e.g., a surface t...
Determine Circle Intersection Status for Rendering Order
Scenario Graphics engine must evaluate multiple pairs of circles to decide rendering order based on intersection. Question Given an array where each e...
Analyze and Clean European Ecommerce Sales Data
sales +----------+-------------+------------+---------+---------+----------------+ | order_id | customer_id | order_date | country | revenue | product...
Determine Most Frequent Product Color in Carts
Scenario Online store wants to know which color of product appears most frequently in customers’ carts. Question Implement a function getMaxColor(colo...
Identify Unique Callers and French Customer Call Percentage
video_calls +---------+-----------+--------------+---------------------+---------------+ | call_id | caller_id | recipient_id | start_ts | ...
Estimate Successful Sign-ups from Super Bowl QR Code Ad
Estimating Sign-ups from a Super Bowl QR Code Ad Background A cryptocurrency company airs a national Super Bowl commercial featuring a bouncing QR cod...
Maximize Distinct Purchases Within Budget Constraints
Scenario Given a customer budget and a list of product prices, determine the maximum number of distinct products the customer can afford. Question Des...
Address Overfitting with L1 Regularization in Regression
Linear Regression with Many Predictors and Few Observations Scenario You fit an ordinary least squares (OLS) linear regression with 500 predictors (fe...
Measure Speaker's Impact Using Propensity Score Matching
Causal Impact of Optional Device Ownership on Engagement (Observational Design) Scenario A new, optional smart speaker is released. Some users purchas...
Calculate Weekly Thread Engagement with Reactions in SQL
messages +------------+--------+----------+--------------+---------------------+ | message_id | sender | receiver | has_reaction | timestamp ...
Calculate Video Call Usage Metrics by Country and Date
video_calls +---------+-----------+------------+---------+----------+ | caller | recipient | ds | call_id | duration | +---------+-----------...
Implement Left Join Using Python Dictionaries Efficiently
Orders +---------+----------+--------+ | order_id| customer | amount | +---------+----------+--------+ | 101 | C1 | 250 | | 102 | ...
Implement Infinite Fibonacci Generator Using Lazy Evaluation
Scenario Testing understanding of Python lazy evaluation and generators. Question Explain what lazy evaluation means in Python and implement a generat...
Compare Ad-Insertion Strategies: Expected Ads and Probabilities
Newsfeed Ad-Insertion Strategies You are evaluating two ways to insert ads into a user's newsfeed. Assume a user views a contiguous sequence of posts....
Monitor Friend-Request System for Quality and Abuse
Friendship +--------------+-------------+---------------------+---------------------+ | requester_id | approver_id | request_ts | approval_ts...
Analyze Conversation Engagement and Reaction Usage Effectively
messages +-----------+--------+----------+--------------+---------------------+ | messageid | sender | receiver | has_reaction | timestamp |...
Resolve Conflict and Communicate Effectively in the Workplace
Behavioral Interview Questions (Onsite — Data Scientist) Context You are interviewing onsite for a Data Scientist role. The interviewer is assessing c...
Calculate French User Engagement and U.S. Call Duration
call_logs +---------+-----------+------------+---------+----------+ | caller | recipient | ds | call_id | duration | +---------+-----------+-...
Analyze Factors Behind 20% Retail Revenue Decline
Retail Revenue Decline Analysis Scenario A retailer reports a 20% decline in revenue compared with a prior, comparable period. Assume revenue is net o...