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 Break-Even Point and Profit Impact Analysis
Break-even and Profit Sensitivity for a Restaurant Context A restaurant has fixed monthly costs (rent, salaries) and a variable cost per customer (foo...
Explain P-Value Reporting and Bootstrap for Coefficient Estimation
Scenario Technical screen — statistical inference checks after regression. Questions 1) You observe a regression output where a coefficient's p-value ...
Design A/B Test for Marketing Campaign Impact Evaluation
Scenario A credit card issuer is testing a marketing campaign that waives the first-year annual fee. You need to design an A/B test to measure increme...
Define Product Metrics: Align Stakeholders, Measure Success, Improve Results
Behavioral Question: Defining New Product Metrics Without Clear Guidance Scenario You are interviewing for a Data Scientist role in a product organiza...
Identify Issues and Redesign Customer-Conversion Chart
Critique and Redesign a Customer-Conversion Visualization Context Assume you are reviewing a chart shown during an interview that attempts to explain ...
How would you test billboard effectiveness?
Pinterest is considering an offline billboard advertising campaign in selected cities to increase brand awareness and downstream user growth. As the d...
Develop Dynamic-Pricing Algorithm for Lyft Balancing Key Factors
Scenario You are tasked with building a dynamic-pricing system for Lyft (a two-sided ride-hailing marketplace) that balances rider demand, rider ETA/c...
Determine Claim Rate for Breakeven in Insurance Portfolio
Weather-Insurance Portfolio Profitability Setup You price a 12-month weather insurance policy. Customers pay premiums upfront for the year. Each polic...
Describe Leading a Project from Ideation to Delivery
Behavioral & Leadership (Data Scientist — Onsite) Scenario A hiring manager wants a deep dive into your most impactful project to gauge ownership, tec...
Investigate Conversion Drop: Metrics, Analyses, Techniques Explained
Investigating a Conversion Drop After a Feature Release Context A new feature was released on an e-commerce platform. Shortly after, overall checkout ...
Estimate Population Mean and Conversion Rate Accurately
Statistical Inference: Hypothesis Tests, Confidence Intervals, Sampling Design, and Truncated Normal Estimation Context You are evaluating a set of pr...
Add two integer strings using digit-adder
Coding Prompt You are given a helper function: - addDigits(a, b) -> (sumDigit, carry) - a and b are single decimal digits (characters '0'…'9' or int...
Compute ad revenue metrics by geography in SQL
You work on a marketplace app that shows shop ads. You are given the following tables. Assumptions - All timestamps are stored in UTC. - “Revenue” is ...
Decide if a dice-betting game is favorable
You are considering a game against a “house” using fair six-sided dice. Rules: - You roll one die; the house rolls one die. - If your roll is strictly...
Choose threshold under asymmetric costs
You own a credit-card fraud classifier deployed as a probability scorer. Choose an operating threshold under asymmetric costs and justify it quantitat...
Design late-tolerant streaming window aggregator
You receive an unbounded stream of events: (event_time, user_id, category). Events may arrive up to 48 hours late and are not ordered by time. Design ...
Define and validate an airline profitability metric
Airline Route Profitability Metric with Quality Guardrails Context You need a single, decomposable primary metric for airline route profitability that...
Compute capacity, staffing trade-offs, and break-even
Capacity, Cost, and Staffing Planning for a 2‑Week Sprint Context - You manage a 3‑person dev‑tools team. Each line of code must be coded, tested, and...
Compare Instagram vs. Facebook using causal experiments
Compare Instagram and Facebook for consumer time and engagement: a) Define a single-objective OEC that captures healthy cross-app ecosystem value with...
Solve window-function SQL without joins
You must use only window functions (no JOINs). CTEs are allowed. Given the schemas and tiny samples below, write SQL for each sub-question and explain...