Data Scientist Interview Questions
Practice 3,071 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."
Create OHLC Aggregates from Tick Data in Python
price_stream +-----------+-------+ | timestamp | price | +-----------+-------+ | 0 | 3 | | 1 | 2 | | 2 | 4 | | 3 ...
Select 10% Users Randomly from User Table
users +----+----------+-------------+ | id | username | signup_date | +----+----------+-------------+ | 1 | alice | 2023-01-02 | | 2 | bob ...
Retrieve First Active and Last Inactive Dates per User
Given a table activity that tracks user activities, write a SQL query to retrieve the first active date and last inactive date for each user. Table Sc...
Identify Shops with Low Weekly Visibility Rates
SHOP_VISIBILITY +-----------+---------+------------+---------+ | shop_id | user_id | view_date | visible | +-----------+---------+------------+----...
Explain P-Value and Errors in A/B Testing
Explain P-Value and Errors in A/B Testing A/B Test Design and Analysis: Core Concepts Scenario You are advising on the design and analysis of an A/B t...
Derive Key Business Metrics Using SQL or Python
Orders +----------+-------------+------------+---------+------------------+ | order_id | customer_id | order_date | amount | product_category | +----...
List Top Customers and Monthly Order Counts in SQL
Orders | order_id | customer_id | order_date | amount | |----------|-------------|------------|--------| | 1 | 101 | 2023-01-05 | 120.5...
Calculate Net Pay Change for Q1 2023 Decreases
EMPLOYEES +-------------+------------+-------+ | employee_id | hire_date | state | +-------------+------------+-------+ | 101 | 2022-04-01 | ...
Calculate Monthly Revenue from Orders in 2023
orders | id | order_date | customer | |----|------------|----------| | 1 | 2023-01-03 | 101 | | 2 | 2023-02-14 | 102 | | 3 | 2023-02-20 | 101 | o...
Modify Instagram Feature: Track User Engagement Metric
Modify Instagram Feature: Track User Engagement Metric A/B Test Design for Modifying a Disliked Social Feature Scenario A social-media company plans t...
Find Top-3 Salaries Per Department Using SQL
employees +----+---------+--------+---------+ | id | name | salary | dept_id | +----+---------+--------+---------+ | 1 | Alice | 120000 | 10 ...
Analyze Social Media Engagement with SQL Queries
info_stream_views +----------+---------+-----------+-------------------------+-----------------------+------------+ | view_id | post_id | viewer_id |...
Analyze Recent User Activity from Video Call Logs
video_calls caller | recipient | ds | call_id | duration 123 | 456 | 2019-01-01 | 4325 | 864.4 032 | 789 | 2019-01-01 | 9395 | 263.7 456 | 032 | 2019-...
Analyze Customer Purchase Patterns Using SQL Query
orders +----------+-------------+-------------+------------+------+ | order_id | customer_id | order_value | order_date | city | +----------+---------...
Simulate Radioactive Decay to Validate Analytical Solution
Scenario Same radioactive-decay problem, but now validate the analytical answer via simulation during the interview. Question Share screen and write r...
Calculate Week-over-Week Revenue Change Using SQL
transactions +----+---------+---------+------------+ | id | user_id | revenue | order_date | +----+---------+---------+------------+ | 1 | 101 | ...
Diagnose Decline in First Day Funding Rate
Diagnose Decline in First Day Funding Rate Diagnostic Case: First-Day Funding Rate Drop Context You are on a product analytics team monitoring onboard...
Apply Multiple Testing Corrections for Valid Results Analysis
Apply Multiple Testing Corrections for Valid Results Analysis Interpreting 30 Parallel A/B Tests With Mixed Results Context - You ran 30 independent w...
Identify Session with Maximum Overlapping Sessions Count
sessions | session_id | start_time | end_time | | 1 | 2023-01-01 09:00:00 | 2023-01-01 10:00:00 | | 2 | 2023-0...
Identify P-Value Limitations and Complementary Approaches
Identify P-Value Limitations and Complementary Approaches A/B Testing: Limits of P-values and Better Decision Practices Scenario Your team is running ...