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."
Design a reproducible data pipeline for modeling
You receive raw clickstream events and a user table. Build a reproducible daily pipeline that outputs user-day features for modeling. It must be idemp...
Compute leakage-safe rolling features in pandas
Using pandas on a 50M-row monthly panel with columns [loan_id, msa, month, property_type, delinquent_90dpd (0/1), upb], create features for each loan-...
Write advanced SQL for sales support analytics
Write SQL for the following schema and tasks. Assume ANSI SQL with DATE_TRUNC and INTERVAL supported. Sample tables (minimal rows shown). accounts +--...
Compute weekly 3-week rolling sums in SQL
Using PostgreSQL, write a single query that outputs, for each calendar week in a given range, the sum of amounts in that week and a rolling sum over t...
Create Views, Insert, and Update Correctly
Treat “today” as 2025-09-01. Use the schema and sample data below to write SQL for each part. Schema: customers(cust_id INT PRIMARY KEY, name TEXT, re...
Compute weighted response rates by job category
You are given a CSV with one row per job posting and the following columns: job_id, job_category, invitations_sent (integer >= 0), provider_responses ...
Rank each team’s top 3 scores in 2024
Using the same schema, compute each team’s top 3 highest-scoring games for season_year = 2024, treating each game from BOTH teams’ perspectives (i.e.,...
Compute churn metrics and rank top students
You have two tasks. Part A (R): You receive a Customers CSV with columns: id (INT), signup_date (YYYY-MM-DD), last_active_date (YYYY-MM-DD), churned (...
Write robust SQL for streaming analytics
Write efficient PostgreSQL SQL for the following streaming analytics tasks. Use the invented schema and sample data below. Handle duplicates, out-of-o...
Compute signup rate and retention from raw logs
Scenario You are analyzing an A/B test for a marketing campaign offering a free 1-month trial. You are given raw “upstream” tables that resemble produ...
Determine Maximum Path Length in Directed Acyclic Graph
Scenario A backend service represents task dependencies as a directed graph; you need to understand how deep the longest dependency chain can get. Que...
Design a Regression Model for Robust Extrapolation Performance
Scenario Onsite machine-learning exercise: your task is to build a regression model using only numerical features that not only fits training data but...
Resolve Team Conflicts and Deliver Beyond Project Scope
Behavioral Case: Team-Based Data Science Collaboration, Scope, and Customer Interaction Instructions - Use the STAR method (Situation, Task, Action, R...
Design Algorithm for Longest Substring with K Distinct Characters
Scenario Tech interview round 2 – sliding-window algorithm Question Design an algorithm that finds the length of the longest substring containing at m...
Calculate Daily Harmful Content View Percentage
VIDEOS +----+-------------+------------+ | id | uploader_id | is_harmful | +----+-------------+------------+ | 1 | 101 | true | | 2 | ...
Assess Cultural Fit and Motivation for Joining CloudTrucks
Behavioral Interview — Data Scientist Phone Screen (CloudTrucks) Scenario A recruiter is assessing cultural fit, motivation, and collaboration style f...
Determine North-Star Metric for CloudTrucks Driver Platform
Product Analytics Case: North-Star Metric and Booking Funnel (Driver Platform) Context You are evaluating the health of a trucking marketplace's drive...
Track Metrics to Measure Push Notification Quality
Scenario A consumer mobile app sends push notifications to drive user engagement. You need to evaluate the quality of these notifications, define what...
Retrieve Top Five Ads by Conversions in 30 Days
ads ad_id | advertiser_id | created_at 1 | 101 | 2024-06-01 2 | 102 | 2024-06-03 3 | 101 | 2024-06-10 ad_i...
Analyze Loan Payments Using Pandas for Key Insights
loan_payments +------------+------------+-------------+-----------+---------+ | loan_id | payment_id | payment_date | amount | status | +------...