Data Scientist Data Manipulation (SQL/Python) Interview Questions
Practice 530 real Data Manipulation (SQL/Python) interview questions for Data Scientist roles. From companies including Meta, Amazon, TikTok, Capital One, DoorDash.
"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."
Compute Heavy-Caller Percentages
You are given two tables that track voice calls and daily active users for a messaging app. Table: call_events - call_id BIGINT — unique call identifi...
Clean and Merge Housing Data
You are given two pandas DataFrames from a house-price screening exercise. house_sales_raw - listing_id INT - sale_price FLOAT, nullable in rows reser...
Write SQL for top drivers and cancellation rates
Question You work on a rideshare / ride-hailing product that connects drivers and riders, with a focus on airport pickups. Using SQL, answer the quest...
Write SQL to compare social-only vs game-only engagement
You are given two tables capturing Oculus app usage. Define an 'active day' as a UTC date on which a user generates at least one event. Consider only ...
Compute adoption, latency, and cross-region transactions
Invented schema: users(user_id INT PRIMARY KEY, user_region STRING, adopted_at TIMESTAMP NULL) transactions(txn_id INT PRIMARY KEY, user_id INT, txn_t...
Write SQL to find top net-revenue products
Using the sample schema and data below, write a single SQL query that returns, for the last 7 days relative to today (use today = 2025-09-01, so the w...
Compare SQL counts, windows, and NULL semantics
You’re given two tables. users(id INT, country STRING, created_at DATE) rows: 1 | US | 2025-08-28 2 | US | 2025-08-30 3 | IN | 2025-08-29 4 | BR | 202...
Find common friends from directed edges
You have a directed edge list that records who followed whom. A mutual “friendship” exists only if both directions appear (A→B and B→A). Schema and sa...
Find least active countries
You are given an ads activity table. Table: ad_activity - ad_id BIGINT — unique ad identifier - advertiser_id BIGINT — advertiser that owns the ad - c...
Clean scores and return top 5 students
Implement a Python function to clean and rank student scores. You are given a table (or DataFrame) students with schema: | column | type | notes | |--...
Calculate CTR and ad revenue
This interview included two SQL tasks. Task 1: Compare CTR during peak and non-peak hours You are given three tables: - ads(ad_id BIGINT, advertiser_i...
Find top category per region in Aug 2025
You are given the following schema and sample data. Schema: - customers(customer_id INT, name TEXT, region TEXT) - orders(order_id INT, customer_id IN...
Write SQL for profit, growth, retention
Write ANSI-SQL (PostgreSQL preferred) for the tasks below. Assume all timestamps are UTC and that "today" = 2025-09-01. Schema: - products(product_id ...
Explain handling very large datasets
Describe a project where you ingested and processed a dataset of at least 500 million rows or 1 TB end-to-end. Detail storage formats and partitioning...
Compute percent of active users with 50+ calls
Problem You work on a Messenger-like app. You want to measure how many active users in Great Britain (GB) today have been heavy callers recently. Tabl...
Analyze Multiple-Account Users in SQL
You are analyzing a product in which a single user can own multiple accounts. Use the following tables: accounts - account_id BIGINT — unique account ...
Find Top-5 Similar Rows
You are given two point-in-time snapshot tables generated on the same day in UTC. There is no direct key relationship between the tables; each row in ...
Compute specialty spend share and top age band
You are given healthcare claims data split across member tables. Tables Assume the following schemas (types may be adapted to your SQL dialect): mem1 ...
Aggregate D1 retention cohorts in SQL
Today is 2025-09-01. Using SQL (optionally outline a pandas approach too), compute daily engagement and D1 retention for the last 7 days (2025-08-26 t...
Write complex SQL on DoorDash data
You are given the following BigQuery-style schema and tiny samples (assume timestamps are UTC; assume promotions.discount_amount is the applied discou...