Data Scientist Data Manipulation (SQL/Python) Interview Questions
Practice 550 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."
Write SQL to infer group-call demand
You are given only 1:1 call logs and a user table. Use SQL to estimate latent demand for a 'Group Call' feature by detecting 10-minute 'call loops' wh...
Compute weighted response rates by job category
You are given a CSV with one row per job posting and the following columns: job_id, job_category, invitations_sent (integer >= 0), provider_responses ...
Label game performance by margin
Given a games DataFrame (or R data.frame) with columns: team_id, opponent_team_id, team_score, opponent_team_score, write code to: (1) Define a functi...
Rank each team’s top 3 scores in 2024
Using the same schema, compute each team’s top 3 highest-scoring games for season_year = 2024, treating each game from BOTH teams’ perspectives (i.e.,...
Find 2023 NCAA championship winner
You are given two tables. Schema: team(team_id INT PRIMARY KEY, team_name TEXT); game(game_id INT PRIMARY KEY, team_id INT, opponent_team_id INT, date...
Diagnose zero IE uploads with SQL
On 2025‑09‑01 ('today'), the dashboard shows image uploads for Internet Explorer (IE) dropped to zero. Write SQL to (a) determine if this is a technic...
Write SQL to flag Venmo ATO
SQL case: You are a Decision Scientist on Venmo’s Fraud (ATO) team. Using the schema and sample data below, write a single Standard SQL query that ret...
Write SQL to backtest refund policy
Using the schema and samples below, write a single SQL query (CTEs allowed) that does all of the following for the last 30 days relative to today = 20...
Write SQL to rank categories by impressions
You are given the following schema and sample data. Today is 2025-09-01. Schema: - users(user_id INT, country_id VARCHAR) - countries(country_id VARCH...
Build panel in SQL; run causal regression
Assume today is 2025-09-01 (UTC). Schema and small samples: users(user_id INT, country STRING, signup_date DATE, platform STRING) Sample: user_id | co...
Compute CTR, RPM, and daily RPM variability in SQL
Write ANSI-Postgres SQL to compute, for each campaign, over the last 7 days inclusive (assume "today" is 2025-09-01, so the window is 2025-08-26 throu...
Write SQL for ads metrics and variability
Write ANSI SQL to compute daily and campaign-level metrics, including averages and standard deviations of daily CTR and CPC, using the schema and samp...
Compute ARPDAU/ARPPU by country
Using only the two tables below, write a single SQL query that returns, for each day and country in the last 7 days inclusive (2025-08-26 through 2025...
Write SQL to flag suspect payments and chargebacks
Assume today is 2025-09-01. Using only CASE WHEN and JOINs (no window functions required), write a single SQL query that produces, for each user with ...
Write robust SQL for streaming analytics
Write efficient PostgreSQL SQL for the following streaming analytics tasks. Use the invented schema and sample data below. Handle duplicates, out-of-o...
Fix dash dates and aggregate watch time
You receive a CSV of ad viewing logs where the date column repeats only on the first row of each block and subsequent rows use a single dash '-' to in...
Write one SQL for exam scores aggregation
You are given an exam database. Write a single SQL statement (CTEs allowed; one final statement only) that satisfies all three requirements below. You...
Compute paid subscriber YoY counts by month
Write a single SQL query (PostgreSQL) that returns calendar-month counts of new paid subscribers starting from 2019-06-01 (inclusive) through the late...
Solve advanced SQL for streaming analytics
You are given minute-level streaming telemetry. Each row in minute_streamed represents one minute during which a streamer was live; each row in minute...
Merge ad CSVs and compute CTR
Using SQL, clean and merge four CSVs and answer all parts exactly. Schema and sample rows (assume types: date is DATE, others INT/VARCHAR): platforms(...