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."
Implement Data Structure for Top-K Elements in Streams
Scenario Analytics feature that must constantly report the K largest numbers seen so far. Question Implement a data structure that ingests a stream of...
Optimize Feature Selection and Handling in Machine Learning Models
Scenario You are building a customer propensity model to predict the probability that a user will take a desired action (e.g., purchase, subscribe). Y...
Evaluate Success of B2C Chat App with Key Metrics
Scenario A data scientist is asked to define how to evaluate the overall success of a business-to-consumer (B2C) chat application. Task Identify the c...
Identify Potential Users for Instagram Shopping Tab Adoption
Instagram Shopping Tab: Targeting, Metrics, and Trade-offs Context Instagram is launching a new in-app Shopping tab. As a data scientist, you need to:...
Evaluate Responses to Teammate's Missed Deadlines
Behavioral Scenario: Choosing Best vs. Worst Responses Context You are completing a behavioral questionnaire that presents workplace dilemmas. For eac...
Identify Users Interested in Group Video Calls
video_calls caller | recipient | ds | call_id | duration u1 | u2 | 2023-09-01| c100 | 320 u3 | u4 | 2023-09-01| c101 ...
Design A/B Test to Isolate Product Usage Drop Causes
Investigating a 10–11% Product Usage Drop via Experimentation Context You observe that product usage fell by 10% in the U.S. and 11% in Mexico over th...
Present Successful Analytics Project: From Problem to Impact
Behavioral Panel: 10–15 Minute End-to-End Project Presentation Scenario Onsite panel presentation (10–15 minutes) with 4–5 listeners. Prompt Choose on...
Balance Customer Satisfaction with Fraud Prevention: Key Metrics to Track
Balancing Customer Experience and Fraud Prevention Scenario In a consumer app with payments (e.g., in‑app purchases, wallet top-ups, withdrawals, crea...
Determine Key Statistics for Article Comment Distribution Analysis
Analyzing Comment Counts per Article Context You are analyzing the number of comments each article receives on a content website. You have the full di...
Impact of parents joining Facebook on teen engagement
Scenario: Parental Presence and Teen Behaviour on Facebook Context: Facebook’s teen audience (ages 13–17) increasingly overlaps with their parents, wh...
Generate Weekly Revenue and Engagement Summary with Pandas
events | user_id | event_time | event_type | platform | revenue | |---------|---------------------|------------|----------|---------| | 101 ...
Evaluate Cost, Time, Security, Flexibility for Training Options
Scenario Your company is rolling out an organization-wide employee training program. The platform must track completions, integrate with SSO/HRIS, and...
Implement Function to Return First n Prime Numbers
Scenario Quick algorithm screen to gauge Python fluency. Question Implement a Python function that returns the first n prime numbers. Hints An optimiz...
Remove Duplicates While Preserving Order in List
Scenario A data pipeline receives an unordered list of IDs containing duplicates; downstream components require a duplicate-free list while preserving...
Influence Cross-Functional Teams Without Formal Authority
Scenario Snapchat Data Scientist onsite, behavioral and leadership focus. A cross-functional product launch (PM, Engineering, Design, and a partner pl...
Diagnose Discrepancy in A/B Test Conversion Rate Results
A/B Test Design: Personalized Marketing Emails and Conversion Lift Scenario An e-commerce firm wants to send personalized marketing emails to increase...
Resolve Team Conflicts to Improve Delivery Efficiency
Behavioral: Conflict Resolution (STAR) Context You're in a Behavioral & Leadership interview for a Data Scientist role. The interviewer wants evidence...
Assessing whether a new metric A is meaningful for News Feed
Evaluating a Proposed Proxy Metric for News Feed Context A partner team proposes a new proxy metric, metric A, intended to capture "meaningful interac...
Advertising for local businesses boosting popular posts
Boosting Popular Posts for Local SMBs: Definitions, Success Metrics, and Diagnosing Low CTR Context You are evaluating an experiment where small, loca...