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."
Write SQL for theme-park revenue and visits
You are given theme-park ticketing and visits data. Write SQL to answer the following, using the sample schema and tables below. Return both the query...
Find companies similar to a given client
System Design: Retrieve Top-20 Most Similar Companies for Sales Prospecting You are given an anchor client (e.g., The Coca‑Cola Company). Design a sys...
Resolve conflicts and prioritize with stakeholders
Describe a specific time you had to juggle conflicting priorities from Risk, Sales, and Engineering on a payments analytics project. Use STAR with dat...
Diagnose 10–11% usage drop across geos
US usage is down 10% and Mexico is down 11%. List plausible confounders (seasonality, pricing, outages, marketing mix, competitor moves, feature rollo...
Demonstrate Amazon LP with deep follow-ups
Behavioral STAR Stories for Amazon Data Scientist Onsite Context You are preparing for an onsite Behavioral and Leadership interview for a Data Scient...
Prioritize a new warehouse proposal with data
Build vs. Lease vs. Defer: New Fulfillment Center Decision Context You are evaluating whether to open a new fulfillment center (FC) to improve deliver...
Design idempotent daily loads with deduping
You need to load the last 7 days of orders into a large fact table from a noisy staging feed. Assume today is 2025-09-01. Requirements: idempotent rer...
Maximize credit card portfolio profit
Credit Card Approval and Profit Optimization (12‑month horizon) Context You receive 10,000 credit card applications per month. Applicants are grouped ...
Decide whether to partner with Groupon
Decision: Partner with Groupon (Restaurant Unit Economics) Context You are the restaurant owner evaluating a Groupon partnership. The offer structure ...
Compute break-even and simulate diaper inventory
You operate a cloth-diaper service with these weekly parameters: 350 babies served; charge $20 per baby; deliver 80 clean diapers per baby; average us...
Demonstrate leadership under ambiguity
Describe a time you faced an open-ended, lightly guided interview or project where the counterpart had a strong accent and offered little direction. H...
Compute Poisson supply–demand match probability
In a city-day of a two-sided marketplace, customer demand D ~ Poisson(8) and supplier capacity S ~ Poisson(6), assumed independent. (a) Compute P(S >=...
Maximize outfits with distinct colors
You're given counts of items by color; each outfit must contain exactly 3 items, all of distinct colors. You cannot reuse items. Input formats: either...
Implement longest increasing subarray with one deletion
Given an array of integers nums, return the length of the longest strictly increasing contiguous subarray you can obtain by deleting at most one eleme...
Derive distribution of an inverse transform
Change of Variables via the Logistic Map You are given a random variable X with density f_X supported on (0, 1). Define the strictly increasing logist...
Implement left join on Python lists, no packages
Implement a left join in pure Python (no external packages, no pandas). Input: left = list of dicts with key 'id' and arbitrary other fields; right = ...
Detect k events in a sliding window
Implement an algorithm that, for each user, determines whether there exists a set of at least k ACH credit events from distinct device_ids within any ...
Estimate delayed CVR nonparametrically with censored data
Today is 2025-09-01. We need the 14-day conversion rate (CVR14) for impressions served between 2025-08-18 and 2025-09-01, but many conversions occur w...
Estimate shuttle impact with robust causal design
You have individual-level data from 1,000+ sites, several hundred of which adopt a free employee shuttle at different times. Design a causal analysis ...
Resolve a team conflict decisively
Tell me about a time you resolved a significant conflict within a team under time pressure. Include: 1) the root causes (interests, incentives, commun...