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."
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"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."
Assess Customer Value with Varied Contract Terms and Costs
Scenario A subscription network-service provider wants to assess unit economics and portfolio impact under different contract terms and cost structure...
Diagnose Causes and Test Hypotheses for Metric Drop
Scenario A large consumer web/mobile product sees its key business metric drop materially and suddenly. Assume: The sitewide purchase conversion rate ...
Investigate Homepage Experiment Without Control Group: Methods and Metrics
Scenario A social-media homepage team is running experimentation and product-metric analyses on a personalized feed. An intern accidentally launched a...
Analyze A/B Test Results to Inform Stakeholder Decisions
A/B Test: Clean, Analyze, Visualize, and Interpret Raw Log-Level Data Scenario You receive raw, log-level event data for an A/B test on a consumer boo...
Design a Restaurant Recommendation System for Food Apps
Designing a Restaurant Recommendation System for a Food-Ordering App Context You are tasked with designing an end-to-end recommendation system that su...
Evaluate Factors Before Renewing TV-Series Contracts
TV-Series Renewal and Divestiture Assessment Scenario You are advising the CEO on whether to renew a 2-year contract for two series: - Series A: The A...
Assess Cultural Fit and Self-Reflection in Hiring Process
Scenario In the Pinterest Data Scientist onsite loop, hiring-manager and cross-functional panels use past behavior to assess cultural fit, self-reflec...
How to improve complaint resolution
You are given three related tables for a Wayfair-style e-commerce customer-support dataset. complaints - complaint_id STRING - customer_id STRING - or...
Evaluate marketplace interventions
You are a data scientist at a two-sided delivery marketplace. Answer the following product analytics and experimentation cases. For each case, define ...
How to evaluate a new homepage feature
Question PayPal is planning to launch a new homepage feature (for example, a new CTA module, personalized content, or a redesigned layout) and wants t...
Evaluate AI-assisted ads creation feature
You’re launching an AI-assisted ad creation tool for advertisers (it suggests copy/creative and helps generate new ads). You need to evaluate whether ...
Compute this-year spend share of last-year whales
Context You work on an ads analytics dataset. Assume all timestamps are in UTC, and “last year” / “this year” refer to the previous/current calendar y...
How would you build and evaluate a classifier?
You are building a binary classification model for a business use case such as fraud detection, churn prediction, lead scoring, or content moderation....
Compute expected arc length on a circle
On the unit circle (radius \(1\), centered at the origin), pick three points independently and uniformly at random on the circumference. These three p...
Solve three algorithmic tasks in Python
You are given 120 minutes to implement three independent algorithmic tasks in Python. Each task specifies the required input/output behavior, the cons...
Convert a PDF to a CDF
Given a continuous random variable X with probability density function f(x), write code or describe an algorithm to construct its cumulative distribut...
How to forecast bike dock demand
You operate a shared city-bike system. For a given dock (station), you want to predict demand in the next hour. Task Design an approach to predict: - ...
Answer career, manager, and team fit questions
Behavioral Questions Answer the following questions in a structured, interview-ready way: 1. Project deep dive: Walk me through a project you worked o...
Implement Plus One
Given a non-empty array of digits representing a non-negative integer, where the most significant digit comes first and each element is in [0, 9], add...
How would you evaluate upranking shop ads?
Context You work on an ads platform (e.g., FB/IG). The team proposes upranking “Shop Ads” (ads that lead to an in-app shop/catalog checkout flow) rela...