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."
Calculate Cumulative Sum for Each Integer in Table
numbers +-----+ | num | +-----+ | 1 | | 2 | | 13 | | 14 | | 15 | +-----+ Scenario You have a table containing one integer per row; for each row...
Evaluate Integrity in Workplace Culture Through HR Screening
Workplace Culture & Integrity Survey (HR Screening) Context You are completing an HR screening as part of a Data Scientist take‑home project applicati...
Explain Python Virtual Environment Setup and Function Analysis
Scenario Technical screen where candidate and interviewer jointly walk through Python code snippets used in a data-science repository. Question Show h...
Maximize Non-Overlapping Task Scheduling Efficiency
Scenario Job scheduler on a single machine wants to maximise throughput. Question Given tasks with [start, end) times, return the maximum number of no...
Calculate Regional Revenue and Identify Top Customers
Customers | customer_id | name | region | |-------------|-------|--------| | 1 | Alice | East | | 2 | Bob | West | | 3 ...
Calculate Weekly Revenue and Order Count for Standard Deliveries
instacart_orders +----------+---------+---------+------------+---------+--------------+ | order_id | user_id | revenue | created_at | geo | delive...
Design Experiment to Test New Hashtag Recommender Algorithm
Experiment Design: Testing a New Hashtag Recommendation Algorithm Context A social app shows hashtag recommendations to users while composing posts. A...
Determine Old vs. New Users' Shop Visibility Changes
SHOP_VISIBILITY_HISTORY +----------+----------------+---------------------+-------------------+---------+ | user_id | user_signup_dt | action_timesta...
Analyze Trends to Diagnose Decline in Job Applications
Diagnose a Week-over-Week Drop in Job Applications Scenario A job marketplace observes that its daily application count has declined week-over-week. T...
Calculate January-2024 SF Promotion Impact Using SQL Queries
campaign_users +---------+-----------+ | user_id | treatment | +---------+-----------+ | 1001 | control | | 1002 | test | | 1003 | con...
Calculate Total Spend and Identify Key User Metrics
Transactions +----+---------+--------+------------+ | id | user_id | amount | date | +----+---------+--------+------------+ | 1 | 101 | 23....
Estimate one-child household probability
You survey 100 children at a school and ask how many children are in their family. The responses are: - 50 children say their family has 1 child. - 20...
How would you measure causal impact?
Answer the following two analytics interview prompts. Constraints & Assumptions - For causal impact, separate prediction from causal identification. -...
Define and critique a user activity metric
Context You are on a product team and need to define a metric for user activity to be used in dashboards and decision-making. Question 1. Propose 2–4 ...
Reason about MAU error after user ID rehash
A product tracks activity using user_id from login events, and computes MAU as: - MAU (L30D) on date d = number of distinct user_id with at least one ...
Explain Type I/II errors vs precision/recall
Questions 1. Define Type I error and Type II error in hypothesis testing, and map them to false positives and false negatives. 2. Explain how Type I/I...
Answer ownership and ambiguity behavioral questions
Behavioral interview prompts (Data Scientist, Risk / Product Analytics): 1. Tell me about a time data changed a decision. 2. When data quality was bad...
Combine noisy thermometers; compute random-walk correlations
Problem 1: Estimating a true temperature from noisy thermometers Assume the true (fixed) temperature is an unknown constant \(\theta\). 1a) One thermo...
Diagnose metric anomalies and evaluate new algorithm
Context You work on a consumer product that includes an AI calling feature (users trigger calls; the system places AI-assisted calls). The team monito...
Validate in-post restaurant recommendations via experiment
Evaluate In‑Post Restaurant Recommendations: Metrics and Experiment Design Context You are evaluating a new feature that surfaces restaurant recommend...