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."
Analyze User Comment Distribution and Sampling Effects
Analyze User Comment Distribution and Sampling Effects You are analyzing daily comment counts per user. The individual user-level distribution is righ...
Calculate Expected Meetings in Randomly Assigned Rooms
Expected Meetings in Randomly Assigned Rooms You are solving two probability questions about room occupancy. Constraints & Assumptions - In the first ...
How to Design Effective A/B Tests for Onboarding
Design Effective A/B Tests for Onboarding A consumer subscription app is launching a redesigned onboarding flow for newly registered users. The goal i...
Evaluate Soft Skills Through Behavioral Interview Questions
Behavioral and Leadership Interview: Soft Skills You are interviewing for a Data Scientist role in an onsite Behavioral and Leadership round. Prepare ...
Identify SQL Joins and Correct Query Errors
Winner +----+-------+ | ID | Name | +----+-------+ | 1 | Alice | | 2 | Bob | | 3 | Carol | +----+-------+ Loser +----+-------+ | ID | Name | ...
Describe Overcoming Challenges and Persuading Non-Data Colleagues
Describe Overcoming Challenges and Persuading Non-Data Colleagues This is a behavioral interview prompt for a data scientist role. The interviewer is ...
Explore Dataset to Assess Quality and Choose Visualizations
Understanding a New Dataset: Profiling, Quality, and Visualization You receive a new, unfamiliar dataset and must quickly generate insights and visual...
Calculate Probability of Third Card Being an Ace
Calculate the Probability of the Third Card Being an Ace You draw three cards without replacement from a standard 52-card deck with 4 Aces and 48 non-...
Compare Regularization Techniques and Their Use Cases
Compare Regularization Techniques and Their Use Cases This technical phone screen asks about model evaluation, regularization, and regression basics f...
Calculate Ad Insertion Statistics for Two Methods
Ad Insertion Statistics for Two Feed Strategies You are comparing two ways of inserting ads into a 100-post feed. - Option A: Each post independently ...
Determine Normality of Single Observation with Z-Test
Hypothesis Test for One Observation Against a Standard Normal You observe a single numeric value x and want to decide whether it could plausibly have ...
Interpreting confidence intervals to choose a treatment
Feed-ranking Tweaks: Interpret Confidence Intervals and Choose a Treatment You ran online experiments for three feed-ranking tweaks. The primary metri...
Describe Handling Cross-Functional Projects and Changing Priorities
Describe Handling Cross-Functional Projects and Changing Priorities This behavioral prompt evaluates how you collaborate across functions, respond to ...
Analyze New Shops' Activity Compared to Existing Ones
shops +---------+------------+---------------+ | shop_id | created_at | category | +---------+------------+---------------+ | 1 | 2024-01-0...
Answer ancestor-walk queries on a rooted tree
Problem (Tree / Parent Array Queries) You are given a rooted tree with n nodes labeled 1..n, represented by a parent array par[1..n]: - par[i] is the ...
Explain and interpret p-values correctly
Context You are evaluating a change to a fraud decision rule (e.g., a new threshold or step-up authentication rule). You run an experiment comparing C...
Explain list vs tuple in Python
Question In Python: 1. What are the key differences between a list and a tuple? 2. When would you prefer using a tuple over a list? 3. What are the pe...
Evaluate new shop-ads ranking algorithm
You work on a marketplace with shop ads. A new ranking/recommendation algorithm is proposed to promote shop ads more aggressively, but stakeholders ar...
Compute probability of random arithmetic progression triple
You have the integers from 1 to 30 inclusive. You randomly choose 3 distinct numbers without replacement, and all 3-element subsets are equally likely...
Define and estimate prevalence of unhealthy users
Using the same Oculus tables (user_activity, apps), you’re asked: Question “How common are unhealthy users?” Task 1) Propose a concrete, measurable de...