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."
Write SQL for social feed metrics and ties
You are given the following schema (PostgreSQL) and sample rows. Assume UTC timestamps and that friendships are static over the sample window. users(u...
Write SQL to rank categories by impressions
You are given the following schema and sample data. Today is 2025-09-01. Schema: - users(user_id INT, country_id VARCHAR) - countries(country_id VARCH...
Build panel in SQL; run causal regression
Assume today is 2025-09-01 (UTC). Schema and small samples: users(user_id INT, country STRING, signup_date DATE, platform STRING) Sample: user_id | co...
Diagnose and reverse an adoption-rate decline
Problem: Investigating a 7pp Drop in Google Meet Enterprise Adoption Rate Context Over the last 4 calendar weeks, enterprise adoption rate has fallen ...
Implement deduped CTR/RPM aggregator over event stream
Implement a Python function to compute per-day, per-campaign CTR and RPM from an event stream with possible out-of-order and duplicate click events. I...
Compute ARPDAU/ARPPU by country
Using only the two tables below, write a single SQL query that returns, for each day and country in the last 7 days inclusive (2025-08-26 through 2025...
Write SQL to flag suspect payments and chargebacks
Assume today is 2025-09-01. Using only CASE WHEN and JOINs (no window functions required), write a single SQL query that produces, for each user with ...
Evaluate friend-interaction feature with network interference
Experiment Design: Network-Aware Test for a "Friend Interaction Boost" in Feed Ranking Context You plan to ship a ranking change that boosts items in ...
Explain motivation and behavioral principles
Behavioral & Leadership — Data Scientist Technical Screen Instructions Provide specific, first-person examples with quantifiable outcomes and the conc...
Fix dash dates and aggregate watch time
You receive a CSV of ad viewing logs where the date column repeats only on the first row of each block and subsequent rows use a single dash '-' to in...
Write one SQL for exam scores aggregation
You are given an exam database. Write a single SQL statement (CTEs allowed; one final statement only) that satisfies all three requirements below. You...
Match Year-2 profit to Year-1
Target Profit Volume Across Two Years Context You sell only classic burgers. Year 1 has negligible fixed costs; Year 2 introduces new fixed costs. The...
Decide goal under ambiguity
Choose the Primary Goal for a New Subscriber-Only Benefit You are the PM/data lead for a subscription product planning a new subscriber-only benefit. ...
Learn complex topic fast under deadline
Behavioral Prompt: Rapid Ramp-Up on a New Analytical Framework You had to learn a new analytical framework in under a week to deliver a high-stakes re...
Compute paid subscriber YoY counts by month
Write a single SQL query (PostgreSQL) that returns calendar-month counts of new paid subscribers starting from 2019-06-01 (inclusive) through the late...
Solve multi-part SQL with sliding windows
Assume 'today' is 2025-09-01. You are given the following tables. users(user_id INT PRIMARY KEY, signup_date DATE) orders(order_id INT PRIMARY KEY, us...
Formulate hypotheses and metrics for video-pin ramp
Experiment Design: Increasing Video Pins in Pinterest Home Feed Context Pinterest wants to increase the proportion of video pins in the Home Feed to b...
Solve SQL CTR and Python analytics tasks
Part A — SQL: Compute click-through rate (CTR) by pin_format for US new users. New users are those whose signup_date is within 30 days (inclusive) of ...
Design SQL cleaning, mapping, dedupe, and keying
Assume PostgreSQL 15. You may choose a different SQL dialect if you clearly state it and adapt syntax accordingly. Schema and small sample data: - Tab...
Solve advanced SQL for streaming analytics
You are given minute-level streaming telemetry. Each row in minute_streamed represents one minute during which a streamer was live; each row in minute...