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."
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"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 Engagement Metrics for Video-Calling App
Calls +--------+-----------+------------+---------+----------+ | caller | recipient | ds | call_id | duration | +--------+-----------+--------...
Address Overfitting in Supervised Learning Models
Bias–Variance Trade-off and Reducing a Train–Test Performance Gap Scenario You are evaluating a supervised learning model and observe that training ac...
Describe Overcoming Obstacles and Taking Calculated Risks
Behavioral: Calculated Risk and Anticipated Obstacle (STAR) Context You are interviewing for a Data Scientist role in an Amazon leadership phone scree...
Determine If Two Strings Are Anagrams Efficiently
Scenario Backend service needs to verify whether two user-provided strings are anagrams for text-matching features. Question Implement a Python functi...
Calculate Recent Post Views and Reactions for Social Media
info_stream_views +---------+-----------+--------------+----------+------------+ | post_id | viewer_id | relationship | duration | ds | +-----...
Evaluate Success Metrics for Facebook Groups and New Features
Facebook Groups — Success Metrics, Prioritization, and Local "Circle" Opportunity Sizing Context You are evaluating Facebook Groups and a potential ne...
Analyze Streaming Data with SQL for Monthly Trends
minute_streamed +---------------------+------------------+------------+--------------------+ | time_minute | streamer_username| category | 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:...
Compute Daily Revenue by Creation Source
active_ads date | ad_id | advertiser_id | creation_source | revenue 2023-09-01 | 1001 | 17 | mobile_app | 150.00 2023-09-01 | 1...
Determine Demand for WhatsApp Group Video-Calls
Opportunity Sizing and Experimentation Plan for WhatsApp Group Video Calls Scenario WhatsApp is considering launching a new group video-call feature (...
Solve Python Challenges: Reverse String, Palindrome, Fibonacci, Unique List
Scenario Live coding round – four quick Python exercises Question Implement a function that reverses a string in-place. Write code that returns True i...
Solve Aptitude Test: Logical, Numerical, Verbal Reasoning
Scenario Pre-employment aptitude screen assessing logical, numerical and verbal reasoning within a strict time limit Question You have 15 minutes to s...
Calculate Adoption and Transaction Rates, Identify Cross-Region Sales
user_txn +---------+-------------+------------+---------------+------------------+---------------------+ | user_id | user_region | adopted_at | transa...
Measure Ultrafast Delivery's Impact Using Synthetic Control Method
Scenario Instacart launched Ultrafast Delivery in Miami two months ago and wants to measure its causal impact on user order volume. Assume you have pa...
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...
Determine Success Metrics for New Group Video-Call Feature
Scenario Meta is exploring a new group video-call feature. Questions 1. Beyond the provided tables/logs, what additional data sources or surveys would...
Normalize Columns in Binomial Matrix Efficiently
Scenario Write code that creates a 100×100 matrix of Binomial(1, 0. 5) samples and normalizes each column so it sums to 1. Question Provide an efficie...
Determine Product Buyer Count and Interaction Percentage
interactions +-----------+----------+------------+----+------------+ | seller_id | buyer_id | product_id | li | create_date| +-----------+----------+-...
Annotating and forecasting a long‑tail distribution
Scenario You are analyzing daily share counts across many pages on a social platform. The cross-sectional distribution of per-page shares on any given...
Employ Collaborative Filtering for Personalized Recommendation Lists
Scenario You are releasing a new recommendation feature that must generate and assign personalized, ranked product lists for each user at scale. Users...