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."
Calculate survey response and quality metrics in SQL
Compute survey response-rate and quality metrics from event data. Assume "today" = 2025-09-01, and compute over the last 7 days (2025-08-26 to 2025-09...
Write SQL to compare exclusive category engagement
You are given session-level data and must compare engagement between users who exclusively used the 'social' category versus those who exclusively use...
Aggregate weekly revenue and attribute 4% drop
Write SQL over the following schema to: (A) compute weekly revenue by ISO week (Monday–Sunday) from orders, excluding cancelled/refunded; revenue_usd ...
Audit flight data quality from metadata
You’re given an airline on‑time dataset and a one‑page “Metadata” slide that claims: flight_date (string, local time), dep_time/arr_time (HHMM local),...
Write SQL to localize anomaly and funnel
Given the schema and toy data below, write SQL to (a) validate instrumentation vs behavior change, (b) localize the 2025-09-01 Likes drop by app_versi...
Transform retail data with pandas groupby/merge/concat
Using pandas only (groupby/agg/merge/concat; no for-loops), write code to answer the sub-questions below on the following small dataframes. Assume tim...
Write SQL to localize trading drop contributors
Use the schema and samples below. Unless stated, treat a user as active on a day if they attempted any order (any status). Dates are inclusive. Schema...
Build a cohort dashboard with Streamlit and SQL
You are given three tables and asked to build a minimal Streamlit app that helps a PM explore weekly cohort retention and ARPU by country. Assume SQL ...
Compute last-to-previous ad impression gaps
Given impressions(ad_id INT, user_id INT, impression_ts TIMESTAMP) with multiple impressions per (user_id, ad_id), write a single SQL query to return,...
Compute per-player daily cumulative games with windows
Write a SQL query to output, for each player_id and each calendar date present in the data, the cumulative number of games played up to and including ...
Design a reproducible data pipeline for modeling
You receive raw clickstream events and a user table. Build a reproducible daily pipeline that outputs user-day features for modeling. It must be idemp...
Compute leakage-safe rolling features in pandas
Using pandas on a 50M-row monthly panel with columns [loan_id, msa, month, property_type, delinquent_90dpd (0/1), upb], create features for each loan-...
Write advanced SQL for sales support analytics
Write SQL for the following schema and tasks. Assume ANSI SQL with DATE_TRUNC and INTERVAL supported. Sample tables (minimal rows shown). accounts +--...
Compute weekly 3-week rolling sums in SQL
Using PostgreSQL, write a single query that outputs, for each calendar week in a given range, the sum of amounts in that week and a rolling sum over t...
Create Views, Insert, and Update Correctly
Treat “today” as 2025-09-01. Use the schema and sample data below to write SQL for each part. Schema: customers(cust_id INT PRIMARY KEY, name TEXT, re...
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 ...
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.,...
Compute churn metrics and rank top students
You have two tasks. Part A (R): You receive a Customers CSV with columns: id (INT), signup_date (YYYY-MM-DD), last_active_date (YYYY-MM-DD), churned (...
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...
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...