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."
Compute SHOP spend share and model performance
You work on ads measurement. Advertisers can drive users to either Facebook Shop ('SHOP') or their own website ('WEBSITE'). After an ad is shown, you ...
Answer common investment-bank research interview prompts
You are interviewing for a role related to equity research / research within an investment bank. In an initial screening (written or video), you are a...
Build a regression model for wind power output
Task: Snapshot Regression for Turbine-Level Power Prediction (Non–Time-Series) You are given turbine-level SCADA snapshots and concurrent weather data...
LinkedIn Product Case Opportunity Sizing
LinkedIn Product Case: Segmentation, Opportunity Sizing, and Adoption Prediction You are interviewing for a Data Scientist role focused on analytics a...
What features and feature selection would you use?
Context You are building an ML system to rank/promote shop ads in an e-commerce feed/search page. At serving time, the system may score candidate shop...
Analyze an A/B test and present recommendation
You are given an offline take-home style project before an onsite interview. You must analyze an A/B test and present your findings in slides. Assume ...
Implement factorial and count trailing zeros
Answer the following coding questions in Python. 1) Implement factorial Implement a function factorial(n) that returns \(n!\) for a non-negative integ...
Explain why IG Story usage exceeds Facebook
Product analytics case: Instagram vs Facebook Stories You work on Stories across two apps: Instagram (IG) and Facebook (FB). A dashboard shows that St...
Write conditional aggregation SQL queries
Question Write an SQL query to compute the total amount for rows satisfying a condition, comparing approaches that use SUM(CASE WHEN … THEN … END) ver...
Compute variance of trading profits
Symmetric Random Walk Trading Strategy: Profit Variance and Expectation Setup - Let S_t be a simple symmetric random walk with S_0 = 0 and increments ...
Estimate Fake Accounts Using Data Signals and Sampling
Estimating Fake Accounts on a Social Network Background A large social platform wants to estimate the proportion and absolute count of fake accounts o...
Analyze Recent User Activity from Video Call Logs
video_calls caller | recipient | ds | call_id | duration 123 | 456 | 2019-01-01 | 4325 | 864.4 032 | 789 | 2019-01-01 | 9395 | 263.7 456 | 032 | 2019-...
Resolve Ties for Top-10 Users in SQL Query
Oculus_Scores +---------+-------+ | user_id | score | +---------+-------+ | u1 | 95 | | u2 | 92 | | u3 | 90 | | u4 | 90 ...
Create Country-Level Spend Report Using Pandas
users +---------+---------+ | user_id | country | +---------+---------+ | 1 | US | | 2 | CA | | 3 | US | +---------+-...
Investigate Why DAU Stagnates Despite High Downloads
Investigating High Daily Downloads but Flat DAU Scenario Adobe Express reports approximately 1M daily downloads, yet daily active users (DAU) remain f...
Compare Instagram and Facebook Stories Using Key Performance Metrics
Scenario You are a data scientist tasked with quantitatively comparing the success of Instagram Stories versus Facebook Stories. Question 1. Define wh...
Design A/B Test for New Recommendation Algorithm Launch
A/B Test Design: New Recommendation Algorithm Objective Design a rigorous A/B test to estimate the incremental impact of a new recommendation algorith...
Analyze Mobile Promo Orders with SQL Query and Metrics
orders +-----------+---------+--------------+------------+-----------+----------+ | order_id | user_id | order_amount | order_date | is_mobile | is_p...
Predict User Churn with Effective Modeling Techniques
Predicting User Churn for a Subscription App Context You are building a model to predict which active subscribers are likely to churn soon so the team...
Calculate Monthly Conversion Rate and Average Order Value
page_views +-----------+---------+---------------------+ | user_id | page_id | view_timestamp | +-----------+---------+---------------------+ |...