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."
Analyze Hashtag Follow Behavior with SQL Queries
following_behavior +------------+---------+-----------+---------------+ | date | user_id | hashtag_id| hashtag_source| +------------+---------+-...
Count, Return, Find, and Select in SQL Queries
orders +----------+--------------+------------+--------+ | order_id | customer_id | order_date | amount | +----------+--------------+------------+---...
Optimize Predictive Analytics: Feature Engineering to Model Evaluation
End-to-End Predictive Analytics Project Walkthrough You are interviewing for a Data Scientist role. The interviewer asks you to describe a predictive ...
Test If Initial Video Uploads Are Shorter Than Later Ones
Hypothesis Test: Are Users' First Video Uploads Shorter? You are given event-level data for a video-sharing product. Each record represents a publishe...
Implement Data Structure for Top-K Elements in Streams
Scenario Analytics feature that must constantly report the K largest numbers seen so far. Question Implement a data structure that ingests a stream of...
Consolidate and Rank Global Salaries in USD
employees_us +---------+----------+--------+---------+ | emp_id | name | salary | country | +---------+----------+--------+---------+ | 1 |...
Analyze Global Engagement and Impressions with SQL Queries
impressions +---------+---------+----------+----------------+ | user_id | country | category | impression_cnt | +---------+---------+----------+------...
Calculate Weekly Revenue and Order Count for Standard Deliveries
instacart_orders +----------+---------+---------+------------+---------+--------------+ | order_id | user_id | revenue | created_at | geo | delive...
Analyze User Purchase Behavior in Online Marketplace Data
user_events +----------+------------+---------------------+-------------+ | user_id | event_type | event_timestamp | product_id | +----------+--...
Implement Python Function for Statistical Test P-Values
Scenario You need a utility that calculates p-values for one-sided and two-sided statistical tests. Question Write a Python function compute_p_value(s...
Sample and Simulate Price Adjustments in R with dplyr
Products +----+-----------+-------+ | id | product | price | | 1 | phone | 500 | | 2 | tablet | 300 | | 3 | laptop | 1000 | | 4 |...
Consider Key Factors Before Launching New Credit Card
New Credit Card Launch: Factors to Assess A retail bank is considering launching a new general-purpose consumer credit card. You are asked to outline ...
Design A/B Test to Isolate Product Usage Drop Causes
Investigating a Product Usage Drop with Experiments You observe that product usage fell by 10 percent in the U.S. and 11 percent in Mexico over the sa...
Find Maximum Sum of Contiguous Subarray Length k
Scenario Monitoring website traffic and needing the highest traffic within any fixed-length time window. Question Given an array of positive integers ...
Identify Date with Highest Total kWh Consumption Using Pandas
meter_readings +----------+------------+---------------+---------+ | meter_id | timestamp | kwh_consumed | city | +----------+------------+------...
Build Accurate Energy Consumption Prediction Model for Utilities
Build an Energy Consumption Prediction Model for Utilities You need to build and productionize a regression model that predicts daily energy consumpti...
Determine Metrics to Evaluate Notification Impact on Users
Determine Metrics to Evaluate Notification Impact on Users Facebook sends several types of push notifications and is considering a new notification th...
Define Metrics and Account for Network and Novelty Effects
Metrics for Notification-Triggered In-App Surveys Meta's notification system triggers optional in-app surveys to measure user sentiment after notifica...
Analyze Recent Orders Dataset with Python/pandas
orders | order_id | user_id | price | created_at | |----------|---------|-------|------------| | 1 | 101 | 20.5 | 2024-01-01 | | 2 ...
Determine Old vs. New Users' Shop Visibility Changes
SHOP_VISIBILITY_HISTORY +----------+----------------+---------------------+-------------------+---------+ | user_id | user_signup_dt | action_timesta...