Data Scientist Data Manipulation (SQL/Python) Interview Questions
Practice 542 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...
Write SQL to flag coordinated fake accounts
Assume today is 2025-09-01. Schema and tiny samples: users(user_id, created_at, country) 1 | 2025-07-01 | US 2 | 2025-08-10 | IN 3 | 2025-08-15 | US 4...
Exclude free subscribers via anti-join
Extend your previous monthly new-subscriber + YoY query to exclude companies that ever received a free subscription, using an anti-join against Free_S...
Compute monthly new subscribers and YoY deltas
Write a single SQL query that returns monthly counts of new subscribers starting at 2019-06, plus year-over-year (same-month prior year) comparisons. ...
Design logical model and consumption
Design a logical data model and consumption layer supporting business and technical services architecture. Provide an ERD‑level description for Accoun...
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...
Compute daily net users from event logs
Given an event log, write SQL to compute, for the target date 2025‑09‑01 ("today"), the counts of new users, retained users, churn users, and net user...
Compute churn with re-subscriptions
You are analyzing a free-month subscription experiment. Assume experiment eligibility has already been computed; every user in the experiment table is...
Compute Rolling Averages and Merge Intervals
You are given two independent pandas tasks. 1. Symmetric sliding-window average - Input dataframe df has columns: - row_id INT: unique row order -...
Calculate Pirated Usage and Revenue Loss
You are analyzing theme piracy on an e-commerce platform. Assume the analysis window is 2023-01-01 through 2023-12-31, all timestamps are stored in UT...
Clean and Analyze User Transactions with Python Functions
transactions +---------+---------------------+---------+ | user_id | trans_ts | amount | +---------+---------------------+---------+ | 11 ...
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...
Calculate Ultimate Loss by Policy Term
You work with insurance policy-term loss data. For a given policy term, its ultimate loss is defined as the sum of losses from the current term and al...
Compute time-spent percentage by app category
You work on Oculus app engagement analytics. Tables user_activity - user_id (BIGINT) - date (DATE) — day of activity (assume UTC) - app_id (INT) - ses...
Analyze User Engagement and Spammer Read-Rate in SQL
messages +------------+------------+-------------+--------------+-----------+ | sender_id | receiver_id| message_id | sent_date | read_date | +--...
Identify Top Users with Declined Transactions in SQL
Transactions +----------------+---------+--------+----------+---------------------+ | transaction_id | user_id | amount | status | timestamp ...
Calculate Defect Rate and Identify Top Lanes for Carriers
shipment +-------------+----------+-----------+---------+---------+-------------+-----------+ | shipment_id | order_id | ship_date | carrier | origin ...
Analyze Recent User Activity from Video Call Logs
video_calls caller | recipient | ds | call_id | duration 123 | 456 | 2019-01-01 | 4325 | 864.4 032 | 789 | 2019-01-01 | 9395 | 263.7 456 | 032 | 2019-...
Calculate and Find Average Contacts and Sync Percentage
dw_peers +--------------+---------------+-------------+ | user_id | synced_contact| date_synced | +--------------+---------------+-------------+ ...
Compute and Rank Store Revenue by Region Using Pandas
Sales +------------+---------+------------+--------+---------+ | date | store_id| product_id | units | revenue | +------------+---------+------...