Data Scientist Interview Questions
Practice 3,030 real Data Scientist interview questions for 2026. Covers companies like Amazon, Google, Capital One, and TikTok. Real questions from actual interviews with detailed solutions. These Data Scientist interview questions are drawn from product, analytics, and modeling roles and designed for interview preparation that targets SQL fluency, statistical thinking, and applied machine learning across entry to senior levels. Expect interviews that evaluate product-metric intuition, experiment design and causal inference, and practical ML system tradeoffs. Amazon and Google lean hard on experimentation, metrics diagnosis, and scalable modeling; Capital One emphasizes statistical rigor, risk-modeling, and feature engineering; TikTok focuses on ranking/recommendation thinking, time-series/product analytics, and heavy SQL. Typical preparation includes timed SQL and Python practice, refreshing hypothesis testing and A/B design, and building short case-style stories that tie analysis to product impact.
"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."
Solve estimation and probability brainteasers
This is a set of independent estimation and probability brainteasers of the kind asked rapid-fire from a slide deck. Treat each one separately. For ev...
Monthly Cohort Retention
Monthly Cohort Retention A residential building-services company tracks every time a tenant interacts with its mobile app (for example, calling an ele...
Compute Commuter Ride Probabilities
A commuter takes two trips on a given day: one morning commute to work and one evening commute home. On each trip they either use Lyft or they don't. ...
Build a Churn Prediction Model
You are asked to build a churn prediction model for a consumer product. The business wants to proactively identify users who are likely to churn so th...
Design and Interpret an A/B Test
You are a data scientist evaluating a product experiment for a grocery-delivery marketplace. The experiment has three arms: a control group and two tr...
Explain How L1 and L2 Regularization Change Linear-Model Coefficients
Explain How L1 and L2 Regularization Change Linear-Model Coefficients Compare ordinary least squares (OLS), L1-regularized linear regression, and L2-r...
Evaluate Promotions for Uber Eats Users
Uber Eats wants to send promotions or coupons to its users (for example, "$5 off your next order" or "20% off, minimum basket $15"). You are the data ...
Explain Logistic Regression, Backprop, and Adam
Walk through the mathematical foundations that connect logistic regression to modern deep-learning training. The interviewer expects you to write the ...
Interpret and Regularize Regression Models
You are a data scientist building and interpreting regression models on a product dataset at a marketplace company. The outcome variable is a continuo...
How would you test product changes?
You are interviewing for a Product Data Scientist role at a food-delivery marketplace. Answer the following related experimentation cases: 1. Checkout...
Compute a Rolling Seven-Day Revenue Sum with Missing Dates
The source report identified a hard SQL question about a rolling sum but did not preserve its schema or exact output. The following is a self-containe...
Assess a Distribution and Derive Coin-Toss Expectations
Prompt The report preserved two topics: assessing a data distribution and finding a coin toss's expectation and distribution. Part 1 structures the fi...
Reverse a Character Array In Place
The interview report preserved only the core exercise: reverse a string without using a built-in reversal method, then discuss time and space complexi...
Explain Core ML Concepts
You are interviewing for a senior AI/ML-oriented Data Scientist role at a financial institution (J.P. Morgan). This is the "ML fundamentals" portion o...
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...
Design experiments for payments, search, and promotions
You are a Data Scientist supporting a consumer marketplace app (users search restaurants and place orders). Answer the following product experimentati...
Estimate ads ranking revenue impact
You are the data scientist for an ads ranking team at a large social platform. The team has built a new ranking algorithm for feed ads. The new model ...
Evaluate NLP Classification Models
You are interviewing for a Data Scientist internship at Amazon. The interviewer asks you to walk through how you think about an NLP classification pro...
Assess Routing Experiment Validity
A ride-hailing team runs an A/B test in San Francisco in July 2024 for a new routing algorithm intended to reduce time to pickup, abbreviated TTP. You...
Compute Parking Clustering Probability and P-Value
There are 20 parking spaces in a row, numbered $1$ through $20$. Four cars park uniformly at random in four distinct spaces, so every subset of $4$ sp...