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."
Compute C/T metrics from bookings and visits
Given two tables, compute control vs treatment (C/T) metrics, apply 24‑hour attribution, and generate a daily plot. Treat “today” as 2025‑09‑01; use t...
Explain Chunking for Financial RAG
Suppose you are building a retrieval-augmented generation (RAG) assistant over long financial research reports, filings, and policy documents. Explain...
Should Uber double member discounts?
Uber is considering increasing the member discount on rides from 5 percent to 10 percent. This can affect rider demand, driver supply, marketplace bal...
How Does Removing Zeros Affect Sharpe?
Suppose a return series has 2n observations. Exactly n observations are 0, and the remaining n observations are non-zero returns x1, x2, ..., xn with ...
Diagnose Weekly Session Conversion Anomalies
You are a Data Scientist supporting an e-commerce platform. You receive a weekly time-series dashboard covering the past three years. The dashboard in...
How to estimate feature impact on usage time
Problem A product team believes a new feature (or a variable you can influence, e.g., enabling notifications, new feed ranking, new UI) changes user t...
How would you choose between shows?
You are a data scientist at a streaming company similar to Netflix or Hulu. Leadership wants a recommendation on whether to renew an existing series o...
Write SQL for seller and vehicle metrics
You are working with a marketplace dataset. Table 1: listing_interactions - buyer_id BIGINT - seller_id BIGINT - interaction_date DATE - product_id BI...
Analyze Pirated Theme Usage Impact
An e-commerce platform lets shops install marketplace themes. Some themes are paid, and a shop should have a valid purchase/license before using a pai...
Describe your best team and your role
Question This is a two-part behavioral question. Answer both parts with concrete, specific examples (use STAR where relevant), and connect what you va...
How compare Waymo turning trajectories statistically
Problem You have aerial-drone data that records the 2D turning trajectories of vehicles passing through multiple intersections. Each trajectory corres...
Should DoorDash add bicycle dashers?
DoorDash is considering onboarding bicycle couriers in a dense urban market that currently relies mostly on car or scooter dashers. As a Data Scientis...
Predict driver acceptance
Design an end-to-end machine learning approach to predict driver acceptance probability in a ride-sharing or delivery marketplace. Assume that when a ...
Solve Markov, OLS-rotation, and coin-toss probability
Answer the following three interview questions. 1) Basic properties of a Markov (transition) matrix Let \(P\) be a transition matrix of a (time-homoge...
Explain why the t-statistic helps
Suppose you estimate an effect size \(\hat{\beta}\) in a regression model or an A/B test and compute a standard error \(SE(\hat{\beta})\). Explain why...
Optimize CUDA GEMM with tiling and coalescing
CUDA Execution Model, Memory Hierarchy, and GEMM Kernel Design You are interviewing for a Data Scientist / GPU-software role at NVIDIA. The interviewe...
Design DoorDash Marketplace Experiments
You are interviewing for a Data Scientist role at a food-delivery marketplace such as DoorDash. The marketplace has three sides: customers, restaurant...
Diagnose completed orders drop in Los Angeles
You are a data scientist at DoorDash supporting the consumer pricing team. The number of completed delivery orders in Los Angeles has dropped meaningf...
Write SQL to compute campaign net revenue
Using the schema and sample data below, write SQL to produce, for each campaign_id and segment, the following metrics for August 2025: total_reached, ...
Maximize watched duration under consecutive-sum limit
You have a list of videos in a feed. Video i has duration d[i] (positive integer). A user has an “attention span” limit A. You want to select a subset...