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 Week-over-Week Revenue Change Using SQL
transactions +----+---------+---------+------------+ | id | user_id | revenue | order_date | +----+---------+---------+------------+ | 1 | 101 | ...
Modify Instagram Feature: Track User Engagement Metric
A/B Test Design for Modifying a Disliked Social Feature Scenario A social-media company plans to modify a disliked Instagram-like feature and must run...
Detect and Reduce Spammy Friend Requests Effectively
Detecting Spammy Friend Requests Context Assume a consumer social platform where users can send friend requests (optionally with a short message). The...
Explain Window Functions and Joins in SQL and Python
TABLE transactions | transaction_id | user_id | merchant | amount | currency | transaction_ts | | 1001 | 17 | Walmart | 45.80...
Identify Pirate-Themed Custom Themes Using Jaccard Similarity
Scenario Engineering receives two lists and must identify custom themes that look like Pirate themes. Question a) Write a Python function that compute...
Diagnose Business Decline Using Key Data Metrics
Diagnose a Sudden Business Downturn Using Data Context You are the data scientist supporting a large consumer marketplace. Leadership reports a sudden...
Identify Session with Maximum Overlapping Sessions Count
sessions | session_id | start_time | end_time | | 1 | 2023-01-01 09:00:00 | 2023-01-01 10:00:00 | | 2 | 2023-0...
Analyze KPI Drop: Immediate Steps for Stakeholder Persuasion
Behavioral + Mini-Case: Persuading with Data and Responding to a KPI Drop Context You are a Data Scientist interviewing onsite for a role focused on p...
Identify Duplicate Posts by User and Date
posts +---------+---------+---------------------+---------------+ | post_id | user_id | created_at | content | +---------+---------+---...
Calculate Weekly, Monthly Hours Watched by Premium Users
watch_events +-----------+----------+----------------+-----------------------+----------------+ | user_id | video_id | watched_minutes| watched_at ...
Explain Your Career Transition and Motivation for Joining Spokeo
Behavioral Interview — Data Scientist (Onsite) Context You are in an HR/Manager behavioral chat for a Data Scientist role at Spokeo. Prepare concise, ...
Verify Machine-Learning Fundamentals for E-commerce Recommendation Platform
Rapid ML Fundamentals Check — Recommender Systems Context You are interviewing for a data-science role on an e‑commerce recommendation platform. The h...
Retrieve Ad Metrics and Rates for Last 7 Days
ads +--------+---------------+----------+ | ad_id | advertiser_id | ad_type | +--------+---------------+----------+ | 101 | 1001 | image...
Resolve Conflicts and Convince Skeptical Stakeholders Effectively
Scenario You are an IC-level data scientist (IC5-or-below) working on fast-paced, cross-functional initiatives at a large tech company. The interview ...
Generate Daily Unique User Views for Each Shop
shop_views +---------+---------+---------------------+ | user_id | shop_id | view_time | +---------+---------+---------------------+ | 101 ...
Investigate Causes of Decline in Facebook Group Comments
Scenario A sharp decline in Comments per Post (CPP) was observed in Facebook Groups last week. Task Outline a step-by-step investigation plan to diagn...
Explain Shell Script Line-by-Line for Data Science Workflows
Scenario Technical screening for a Principal Data Scientist: reviewing shell script and Python classes Question Explain, line by line, what the provid...
Analyze Pirate Theme Usage Growth Over Time
themes +----+--------------+-----------+ | id | name | is_pirate | +----+--------------+-----------+ | 1 | Pirate Red | true | | 2 | ...
Expand Internationally: Data and Strategy for Market Entry
Behavioral + Product Sense (Onsite) Context You are interviewing for a Data Scientist role at a product-led software company. In this onsite round, yo...
Identify Number Pairs Adding to Target in Array
Scenario Coding round to identify all number pairs that add up to a target in an array containing duplicates. Question Given an integer array (may con...