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."
Decide content volume and price under uncertainty
How would you decide how many shows to produce and what subscription price to set for an online-content startup? Lay out: a) an optimization objective...
Clarify ambiguous requirements under pressure
Behavioral & Leadership Prompt — Problem Understanding and Clarification (Data Scientist, Technical Screen) Part 1 — Past Experience Describe a time y...
Plan and analyze a ranking A/B test
Experiment Design: New Search Ranking Feature Context You are designing, running, and analyzing an online controlled experiment to evaluate a new sear...
Explain RF optimization and variable-importance pitfalls
Optimize and Regularize a Random Forest Regressor for Tabular Data Context: You are training a Random Forest (RF) regressor on tabular data and need t...
Compute energy needed for 10% ROI
A proposed plant must deliver at least a 10% annual ROI on an initial investment of $400M. Annual economics (assume all numbers are annual unless note...
Optimize precision–recall under class imbalance
You have extreme class imbalance (positive rate ~1%). You score 12 examples as follows (id, true_label, score): A,1,0.92; B,0,0.90; C,0,0.88; D,0,0.70...
Compute adoption, latency, and cross-region transactions
Invented schema: users(user_id INT PRIMARY KEY, user_region STRING, adopted_at TIMESTAMP NULL) transactions(txn_id INT PRIMARY KEY, user_id INT, txn_t...
Diagnose and experiment to reduce late deliveries
Two-Sided Delivery Platform: Rising Late Deliveries You are the first analyst on a two‑sided delivery platform that handles both food and parcel order...
Extract companies from noisy text
Extracting Company Names from Noisy Resumes and Web Snippets Context You receive messy resume text (PDF-to-text/OCR, varying casing) and scraped web s...
Diagnose unbiasedness in a messy A/B test
A/B Test ITT Unbiasedness and Remedies Under Noncompliance, Missing Logs, Interference, and Early Stopping Setup - Design: User-level 50/50 A/B test s...
Compute monthly CRR with merges and gaps
You are given PostgreSQL tables user_profile(user_id, signup_ts, country, is_employee, is_test), user_events(user_id, event_ts, event_type, revenue, p...
Write SQL to find top net-revenue products
Using the sample schema and data below, write a single SQL query that returns, for the last 7 days relative to today (use today = 2025-09-01, so the w...
Improve low R² without p‑hacking
Predicting Contribution per Order with Low R² Context You are modeling contribution per order (a continuous per-order outcome such as margin or profit...
Design a battery-life predictor and cold-start strategy
Smartphone Time-to-Empty (TTE) Prediction — Baseline, Features, Cold Start, Evaluation, and Monitoring Context You are building a per-device predictor...
Solve and optimize 3Sum and variants at scale
Implement a function that returns all unique triplets (i, j, k) of indices whose values sum to a target T, with strong performance and deduplication g...
Experiment on increasing order notifications
Experiment Design: Increasing Order‑Related Push Notifications Context You are asked to design, measure, and make decisions about increasing order‑rel...
Compare SQL counts, windows, and NULL semantics
You’re given two tables. users(id INT, country STRING, created_at DATE) rows: 1 | US | 2025-08-28 2 | US | 2025-08-30 3 | IN | 2025-08-29 4 | BR | 202...
Compute power and interpret uplift metrics
A/B Test on Conversion: Powering, Inference, CUPED, Multiple Testing, and Clustering You are running a two-arm A/B experiment on a binary conversion o...
Explain tackling ambiguity and defending a decision
Behavioral: Ambiguous Analytics With Incomplete Data and a Tight Deadline Context: You're a Data Scientist interviewing in a technical screen focused ...
Compute profit and break-even for memberships
Grocery Loyalty Program Economics — Year‑1 Incremental Profit and Premium Break‑Even Context: You are evaluating the Year‑1 unit economics of a grocer...