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 for social feed metrics and ties
You are given the following schema (PostgreSQL) and sample rows. Assume UTC timestamps and that friendships are static over the sample window. users(u...
Implement deduped CTR/RPM aggregator over event stream
Implement a Python function to compute per-day, per-campaign CTR and RPM from an event stream with possible out-of-order and duplicate click events. I...
Compute multi-account activity and unread percentages in SQL
You are given two tables. Use them as the source of truth and do not assume any other data. Table: notifications +--------+------------+------------+-...
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...
Solve multi-part SQL with sliding windows
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Solve SQL CTR and Python analytics tasks
Part A — SQL: Compute click-through rate (CTR) by pin_format for US new users. New users are those whose signup_date is within 30 days (inclusive) of ...
Design SQL cleaning, mapping, dedupe, and keying
Assume PostgreSQL 15. You may choose a different SQL dialect if you clearly state it and adapt syntax accordingly. Schema and small sample data: - Tab...
Write SQL for cuisine median delivery times
Use SQL to answer the following. Assume ANSI SQL with window functions and percentile functions available. Treat “today” as 2025-09-01 (inclusive). Co...
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Map sources to functional dataset with SQL
You must produce a functional, consumption‑ready dataset for daily exposure monitoring. Assume “today” = 2025‑09‑01. Use the last 7 calendar days by t...
Query email logs for deliverability insights
Using the schema and sample data below, write SQL to answer parts a–c. Assume timestamps are UTC. Today is 2025-09-01. Schema: - Emails(sent_id INT, m...
Compute CTR by format for new US users
You are given three tables. Write a single SQL query to compute click-through rate (CTR) by pin_format for NEW users in the US, where NEW users are th...
Write SQL for rolling frequency caps
You work on ad serving with per-user rolling 7-day frequency caps at the campaign level. Assume "today" is 2025-09-01 and t0 = 2025-09-01 12:00:00 UTC...
Compute 30-day power users and 7-day retention
Compute 30-day power users and 7-day retention You are interviewing for a Product/Risk Data Scientist role at a crypto exchange. Assume all timestamps...
Write SQL to compute max and min marks
Tables marks | column | type | notes | |---|---|---| | student_id | INT | primary key | | marks | INT | not null | Task Write a SQL query that returns...
Write SQL for character safety and engagement metrics
You are working with a conversational product that has users, AI characters, and conversations. Write SQL queries for each of the tasks below. Assume ...
Compute SHOP spend share and model performance
You work on ads measurement. Advertisers can drive users to either Facebook Shop ('SHOP') or their own website ('WEBSITE'). After an ad is shown, you ...
Calculate Week-over-Week Revenue Change Using SQL
transactions +----+---------+---------+------------+ | id | user_id | revenue | order_date | +----+---------+---------+------------+ | 1 | 101 | ...
Calculate Response Rate and Compare New vs. Existing User Scores
survey_events +---------+------------+-----------+--------------+---------------------+ | user_id | is_new_user| responded | survey_score | event_time...
Identify 3-Person Call Cycles in Video-Calling App
Calls callerid | recipientid | ds | call_id | duration 1001 | 2001 | 2023-02-20| 555 | 180 2001 | 3001 | 2023-02-20| ...