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."
Analyze NYC taxi trips efficiently over last 7 days
Use today = 2025-09-01. Consider NYC taxi trip data over the last 7 days inclusive (2025-08-26 to 2025-09-01, America/New_York). You receive two datas...
Write SQL to rank advertisers and profitability
You are given two denormalized tables. Use ANSI SQL (CTEs allowed) and UNPIVOT (or an equivalent UNION ALL approach if UNPIVOT is unavailable). Table:...
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 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 ...
Write SQL/Python for ACH fraud analytics
As of today (2025-09-01), use the following schema and tiny samples to answer. Provide SQL for the SQL parts and Python for the Python part. Schema - ...
Analyze video flags and reviews with SQL
You are designing SQL queries for YouTube Trust & Safety. Use the schema and sample data below. Unless stated otherwise, treat a flag as reviewed if t...
Build DiD dataset with SQL
Using the schema and sample data below, write SQL to build an individual-day panel suitable for staggered-adoption DiD of the shuttle’s effect on part...
Write SQL/Python for messy event data
Using the schema and sample data below, write: (1) a single SQL query to compute daily metrics for the local date 2025-09-01 in America/Los_Angeles, a...
Write SQL to analyze group-call concurrency
You are given call data and must compute group-call metrics. Schema (timestamps are UTC): Tables: - calls(call_id INT PRIMARY KEY, host_user_id INT, s...
Compute same-day acceptance metrics last week
Assume today is 2025-09-01; interpret 'last week' as 2025-08-25 through 2025-08-31 inclusive, using UTC dates. You have the following schema and sampl...
Append country tables and rank salaries in USD
You have separate country-level employee tables that must be appended and ranked by salary converted to USD using an exchange rate table. SQL schema a...
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...
Build SQL pivot with lookups and currency conversion
You are given the following schema and sample data. Use SQL (or Python with SQL-like transforms) to answer the tasks below. Treat amounts as gross rev...
Add a conditional column in Python
Using pandas, add a derived column to a table based on multiple conditions with strict precedence and missing-value handling. Given the sample DataFra...
Compute CTR and metrics with pandas
Using pandas only, compute banner and story metrics. Assume today is 2025-09-01 and 'last 7 days' means 2025-08-26 to 2025-09-01 inclusive. You are gi...
Define and compute shop visibility in SQL
You own the 'shop visibility' KPI for a marketplace. Define a precise metric and write SQL to compute it over the last 7 days (use today = 2025-09-01,...
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: sum values ≤ each row’s value
Given table numbers(id INT PRIMARY KEY, val INT), return for every row the sum of all val across the entire table that are ≤ that row’s val (i.e., com...
Manipulate data efficiently in Python
Answer the following: (a) Contrast list comprehensions and generators with respect to memory and evaluation; write a generator that yields rolling win...
Query conversion and retention with SQL windows
Schema and sample data (PostgreSQL): users(id, signup_date, country) 1 | 2025-08-20 | US 2 | 2025-08-25 | US 3 | 2025-08-27 | CA 4 | 2025-08-30 | US 5...