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."
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...
Compute Moderation View Metrics
Question You are working on a content moderation analytics problem. You have two tables. Table 1: content_views (one row per user / post / day) - user...
Analyze spend cohort and source shifts
You work on an ads platform. Assume all timestamps are in UTC. Interpret last year as calendar year 2023 and this year as calendar year 2024. Tables: ...
Write SQL for video-call recipients and FR activity
Given the schema and samples below, write ANSI‑SQL to answer both questions. Assume dates are stored in UTC. Today is 2025-09-01, so “yesterday” is 20...
Write SQL/pandas for KPI anomaly
Write SQL (and outline equivalent pandas) for a KPI anomaly investigation. Assume today = '2025-09-01'. Schema: Users(user_id INT, country TEXT, signu...
Write left-join queries with tricky filters
Assume 'today' = '2025-09-01'. Do NOT use window functions (e.g., RANK). Use LEFT JOIN, COUNT(DISTINCT), GROUP BY, HAVING as appropriate. Schema: - us...
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...
Write SQL for retention, conversion, and churn
Assume today is 2025-09-01 (use the user's local day boundaries based on users.tz). Given the following schema and sample data, write SQL to: (a) Comp...
Create and query an e-commerce schema
PostgreSQL only. 1) Create these tables with appropriate types and constraints (choose minimal correct types): products(product_id PK, name NOT NULL, ...
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...
Build DID panel and compute effects in SQL
Using the schema and toy data below, write SQL to construct a user-week panel and compute a clean pre/post DID dataset for first reminder exposure. Re...
Count heavy callers in 7 days
You are given two tables. users - user_id BIGINT PRIMARY KEY - country_code STRING calls - call_id BIGINT PRIMARY KEY - caller_id BIGINT - recipient_i...
Compute ads revenue by geography in SQL
You have ad delivery logs for a shop-ads system. Tables ad_impressions - impression_id STRING (PK) - ts TIMESTAMP (UTC) - user_id STRING - shop_id STR...
Compute this-year spend share of last-year whales
Context You work on an ads analytics dataset. Assume all timestamps are in UTC, and “last year” / “this year” refer to the previous/current calendar y...
Compute ad revenue metrics by geography in SQL
You work on a marketplace app that shows shop ads. You are given the following tables. Assumptions - All timestamps are stored in UTC. - “Revenue” is ...
Solve window-function SQL without joins
You must use only window functions (no JOINs). CTEs are allowed. Given the schemas and tiny samples below, write SQL for each sub-question and explain...
Compute seller counts and vehicle share
You are given two tables: 1. listing_interactions - buyer_id BIGINT - seller_id BIGINT - event_date DATE - product_id BIGINT - listing_...
Write queries to compute salary and budget stats
You are given the following interview tasks. Write solutions in SQL and/or Python (pandas) as appropriate. Task 1 — Second highest salary You have a t...
Count Recent High-Volume Call Users
Given the following tables: users - user_id BIGINT - country STRING - is_active BOOLEAN calls - call_id BIGINT - initiated_at TIMESTAMP - caller_id BI...
Write SQL for CTR and revenue
Write SQL for the following two tasks. Problem 1: CTR during peak vs. non-peak hours You are given three tables: - ads(ad_id BIGINT, advertiser_id BIG...