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."
Find posts with >60s unconnected viewing time
Context You work on a social app where users can view posts. A view can be from a connected user (viewer is friends/connected with the post author) or...
Derive eigenvalues and sum for inverse matrix
Derive eigenvalues and sum for inverse matrix Eigenvalues of an Inverse and Their Sum Context Let A be an invertible n×n matrix (over the real or comp...
Count super-streak segments in an event stream
You are given a time-ordered sequence of events. Each event has: - type, a string or integer event type. - ts, an integer timestamp in milliseconds or...
Identify top exposures and mitigate
Identify top exposures and mitigate Portfolio Risk Identification and Mitigation Proposal Context You are evaluating a commercial/corporate lending po...
Compute EL and RWA from loan data
Compute EL and RWA from loan data Task: Compute Portfolio EL and RWA from Loan-Level PD, LGD, EAD Context You are given an anonymized, loan-level data...
Ensure model ethics and governance
Ensure model ethics and governance Ensuring Model Ethics Across Development and Deployment Context You are interviewing for a Data Scientist role in a...
Measure fake account prevalence
A social platform is concerned about fake accounts. Leadership wants to understand how serious the problem is and whether a new detection model or enf...
Evaluate an ads algorithm change
Your ads team has developed a new ad-ranking algorithm for feed delivery. The new algorithm is expected to improve ad relevance and monetization, but ...
Describe leadership and inclusion examples
Prepare strong behavioral answers for the following prompts: - Tell me about a breakthrough project you led or meaningfully influenced. - Tell me abou...
Compute maximum score using up to 3 categories
Problem A library runs a summer reading program. Each book a student reads earns a certain number of points, and each book belongs to a category. A st...
Decompress an encoded string
Decompress an encoded string Given an encoded string, return its decoded (decompressed) form. Use the following encoding rule: - A positive integer \(...
Explain key ML/stats concepts
Explain key ML/stats concepts You are taking an ML/Stats screening with conceptual multiple-choice questions. Answer the following: 1. CNN vs. RNN ...
Sort a Nearly Sorted Array
Given an array nums of length n in which every element is at most k positions away from its location in the fully sorted order, return the array in so...
Evaluate campaign success and decide new trading pair
Context You are a Data Scientist at a crypto exchange. You work with Growth Marketing and Product to evaluate marketing spend and to make listing/laun...
Define metrics for harmful-content severity
Context You are a Data Scientist on the integrity / harmful-content team for a large social media product. Leadership wants a way to track how bad pol...
Plan DS approach for biker delivery project
You are a Data Scientist supporting a “biker” (delivery rider) product/project for a food-delivery platform. An interviewer gives only a short descrip...
Compute expected coin flips to meet on octagon
Compute expected coin flips to meet on octagon Meeting Time on a Random Walk Around an Octagon Problem Two independent particles start at opposite ver...
Find Longest Increasing Continuous Subarray
Given an integer array nums, return the length of the longest contiguous strictly increasing subarray. "Contiguous" means the elements must appear nex...
Find top buyer in earliest 10-year window
You are given two tables: customers and purchases. Table: customers | column | type | notes | |---|---|---| | customer_id | BIGINT | Primary key | | c...
Design Rideshare Marketplace Causal Analyses
You are a data scientist at a ride-hailing marketplace. Answer the following case prompts as if you were advising product, operations, and marketplace...