Data Manipulation (SQL/Python) Interview Questions

Practice 682 real Data Manipulation (SQL/Python) interview questions for 2026. Data Manipulation (SQL/Python) interview questions cover the core data work hiring teams use to judge day-one competence: translating product metrics into correct queries, handling edge cases (NULLs, late-arriving events, double-counting), writing efficient joins and window functions, and producing readable, reproducible Pandas code. Real interviews with detailed solutions in this category test both correctness and engineering judgment, not just syntax. Expect these questions across analytics and data-engineering loops at companies that weight practical querying heavily — especially Meta, Amazon, and TikTok. Interviewers evaluate problem scoping, test-case thinking, query performance, and clear communication of assumptions. For interview preparation, focus on hands-on practice: timed live SQL exercises, Pandas data-cleaning drills, and walking through tradeoffs when a naive query will be too slow. Practical habits that help in interviews include writing concise, well-commented queries, stating assumptions up front, and verifying results with small, explicit test cases.

682 Questions 114 Companies08.03.2026
Showing 20 results
Role
Capital One logo
Capital One
Easy
Data Analyst

Analyze Mission Outcomes and Allocate Response Units

Analyze Mission Outcomes and Allocate Response Units You receive historical mission-level data for a set of response units. Assume one row represents ...

Data Manipulation (SQL/Python)
14
0
184 people solved
Jul 8, 2026
Affirm logo
Affirm
Medium
Software Engineer

Analyze Returning Borrowers Across Two Days of Logs

Analyze Returning Borrowers Across Two Days of Logs You receive two collections of loan-activity records, one for each of two consecutive days. Each r...

Data Manipulation (SQL/Python)
9
0
124 people solved
Jul 14, 2026
Bytedance logo
Bytedance
Medium
Data Scientist

Find Each User's Earliest Seven-Day Activity Streak

Find Each User's Earliest Seven-Day Activity Streak Write one PostgreSQL SELECT statement or CTE query. Do not create, alter, or modify tables. Schema...

Data Manipulation (SQL/Python)
1
0
8 people solved
Aug 3, 2026
DoorDash logo
DoorDash
Easy
Data ScientistSenior+

Measure Customers Ordering from Bottom-Quartile Restaurants

Measure Customers Ordering from Bottom-Quartile Restaurants Write one PostgreSQL SELECT statement or CTE query. Do not create, alter, or modify tables...

Data Manipulation (SQL/Python)
1
0
9 people solved
Jul 27, 2026
DoorDash logo
DoorDash
Easy
Data ScientistSenior+

Calculate the Monthly Share of High-Frequency Customers

Calculate the Monthly Share of High-Frequency Customers Write one PostgreSQL SELECT statement or CTE query. Do not create, alter, or modify tables. Sc...

Data Manipulation (SQL/Python)
2
0
8 people solved
Jul 27, 2026
Airbnb logo
Airbnb
Medium
Data Scientist

Describe How You Use SQL in Data Science Work

How do you use SQL in your day-to-day data-science work? Describe the kinds of problems you solve, the complexity of queries you can own, and the chec...

Data Manipulation (SQL/Python)
3
0
41 people solved
Jul 8, 2026
DoorDash logo
DoorDash
Easy
Data ScientistSenior+

Find Monthly Top Customers Excluding High-Frequency Users

Find Monthly Top Customers Excluding High-Frequency Users Write one PostgreSQL SELECT statement or CTE query. Do not create, alter, or modify tables. ...

Data Manipulation (SQL/Python)
0
0
7 people solved
Jul 27, 2026
Pinterest logo
Pinterest
Hard
Data Scientist

Implement and Evaluate Pin Similarity in Python

You are asked to compare Pin similarity in Python. Begin by clarifying how a Pin is represented and what “similar” should mean. Then assume the interv...

Data Manipulation (SQL/Python)
5
1
83 people solved
May 17, 2026
Morgan Stanley logo
Morgan Stanley
Medium
Data Scientist

Describe Your Analysis and Visualization Toolkit

Give a recruiter-friendly overview of the data-analysis and visualization tools you use in your work. Explain what each tool helps you accomplish, how...

Data Manipulation (SQL/Python)
3
0
25 people solved
Jul 10, 2026
DoorDash logo
DoorDash
Easy
Data ScientistSenior+

Calculate Monthly Restaurant Sales Growth

Calculate Monthly Restaurant Sales Growth Write one PostgreSQL SELECT statement or CTE query. Do not create, alter, or modify tables. Schema delivery_...

Data Manipulation (SQL/Python)
0
0
5 people solved
Jul 27, 2026
Meta logo
Meta
Hard
Machine Learning Engineer Locked

Find A Low-Quality Annotator From Label Data

Practice a pandas-style data analysis prompt for identifying a low-quality annotator from label data. The question emphasizes cleaning, agreement or g...

Data Manipulation (SQL/Python)
4
0
56 people solved
Jun 2, 2026
Voleon logo
Voleon
Easy
Data Scientist

Analyze a Regression Dataset and Build a Safe File-Processing Utility

Analyze a Regression Dataset and Build a Safe File-Processing Utility You receive a feature matrix X and a continuous target y. After the analysis, im...

Data Manipulation (SQL/Python)
0
0
17 people solved
Jun 1, 2026
Waymo logo
Waymo
Medium
Data Scientist

Analyze User Ride Activity with SQL

Use the following tables to answer four SQL analysis tasks. `text rides(ride_id, ride_date, ride_rating, user_id) users(user_id, city) ` Constraints &...

Data Manipulation (SQL/Python)
6
0
70 people solved
Mar 14, 2026
Meta logo
Meta
Medium
Data Scientist

Calculate Daily Survey Response Rates by Country

The interview report preserved the survey tables and the request to calculate response rate, but not the exact grouping or output contract. The follow...

Data Manipulation (SQL/Python)
30
4
353 people solved
Jul 6, 2026
Spotify logo
Spotify
Easy
Machine Learning Engineer

Query Top Played Tracks Globally And By Country

Given a play_events table with columns user_id, track_id, timestamp, and country, write SQL to return the top N most played tracks globally and the to...

Data Manipulation (SQL/Python)
8
4
143 people solved
Jul 2, 2026
Waymo logo
Waymo
Medium
Data Scientist

Implement a Safe Average Function in Python

Write a Python function average(table) that returns the arithmetic mean of a list of numbers and returns 0 when the list is empty. Explain the functio...

Data Manipulation (SQL/Python)
4
0
44 people solved
Mar 14, 2026
Clickhouse logo
Clickhouse
Medium
Data Engineer Locked

Answer SQL And Data Warehouse Fundamentals For A Data Engineering Interview

Practice data engineering fundamentals across SQL set operations, anti-joins, top-N window queries, and warehouse modeling. The prompt covers UNION ve...

Data Manipulation (SQL/Python)
5
0
39 people solved
May 19, 2026
DoorDash logo
DoorDash
Medium
Data Scientist

Measure Daily Late-Order Rates by Delivery Zone

The original interview report identified a late-order SQL exercise but did not preserve its exact schema. The following is a self-contained practice r...

Data Manipulation (SQL/Python)
18
0
125 people solved
May 7, 2026
Meta logo
Meta
Medium
Data Scientist

Compare Survey Satisfaction for New and Established Users

The interview report preserved the survey tables and the request to compare response levels for new and old users, but it explicitly noted that the in...

Data Manipulation (SQL/Python)
3
0
67 people solved
Jul 6, 2026
Scale AI logo
Scale AI
Medium
Machine Learning Engineer

Debug ML pipeline and build text parser

You are in a hands-on, hour-long ML-engineering working session (Scale AI, Machine Learning Engineer loop). You are given a small ML project — data lo...

Data Manipulation (SQL/Python)
41
0
526 people solved
Sep 6, 2025

Frequently Asked Questions

How difficult are Data Manipulation (SQL/Python) interview questions?
Data Manipulation (SQL/Python) interview questions range from basic to advanced. Entry-level questions test filtering, joins, simple aggregates and pandas groupby, while mid and senior roles push multi-table joins, window functions, deduping, time-series alignment, null-handling, and performance trade-offs. Interviewers at companies that weight this category heavily, such as Meta, Amazon and TikTok, look for correctness, edge-case thinking, readable code, and clear trade-off explanations. The challenge is rarely obscure syntax; it is turning an ambiguous product or metric prompt into a robust query or transformation that scales and survives messy, real-world data.
Where in a typical interview loop does data manipulation appear and what formats should I expect?
Data manipulation shows up across the loop: initial technical screens often include 30 to 60 minute live SQL or Python problems, take-home assignments use Jupyter or SQL editors for end-to-end cleaning and analysis, and on-site rounds dedicate 45 to 60 minutes to deeper problems that combine query writing with product framing or A/B test interpretation. Companies such as DoorDash, Capital One and Meta commonly place heavy emphasis on this category in both phone screens and loop rounds. Expect a mix of live coding, whiteboard-style reasoning about schemas, and short conversations where you must justify assumptions and performance choices.
How long should I prepare for data manipulation interviews?
Preparation time depends on baseline skill and target company. If you already write SQL and pandas daily, focused sharpening of edge cases and timed practice for two to six weeks often suffices. Candidates aiming at heavily SQL-weighted loops at Meta, Amazon or other top firms typically plan six to twelve weeks to rebuild pattern recall, drill window functions, and rehearse product-driven questioning. Prioritize active practice: solve real-schema SQL problems, build small Python notebooks that replicate common ETL steps, simulate timed screens, and do a few mock interviews to practice explaining assumptions under pressure.
What are the key subtopics I must master in SQL and Python for data manipulation rounds?
Master the basics first: joins, aggregations, GROUP BY semantics, and filtering versus HAVING. Move to window functions for ranking, lead/lag and cumulative metrics, and CTEs for readable stepwise transformations. Handle nulls, deduplication, time alignment, string parsing and timezone-aware date arithmetic. In Python focus on pandas groupby, merges, pivoting, boolean indexing, rolling computations and writing clean, vectorized code. Also understand performance considerations: explain why you choose SQL versus Python for a particular workload and how to reduce row explosion or costly cross joins when working with real datasets.
What standout tips and common pitfalls should I watch for during interviews?
Always start by clarifying the metric, sample schema, and edge cases, and sketch expected sample output before coding. Use small example rows to validate logic and state assumptions about nulls, duplicates, and timezones. Prefer readable CTEs or well-commented pandas steps over one-line cleverness. Watch common pitfalls such as double-counting from incorrect joins, applying HAVING instead of WHERE, off-by-one window boundaries, and failing to dedupe before aggregation. Finally, communicate complexity and trade-offs: explain how your solution handles scale, when you would push work into the warehouse, and what tests you would run in production.

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