Land Your DreamData Role
Practice real interview questions, simulate interviews with AI, and build portfolio projects — everything you need to walk into your next interview with confidence.
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Everything You Need to Succeed
From practice questions to portfolio projects — we've got your entire interview prep covered.
Interview Questions
1000+ real coding and concept questions from top companies. SQL, Python, system design, statistics, and more.
Mock Interviews
AI-powered mock interviews that simulate real data science interviews with timed sessions and detailed feedback.
Data Labs
Data projects powered by our cloud hosted Python notebooks, no setup required.
Learning Paths
Free comprehensive SQL and Python paths. 6 modules, 36 lessons, and 160+ questions each.
Performance Insights
Track your skills, benchmark against the community, and build your public data profile.
AI StrataTools
Validate and optimize your code in real environments.
Practice Questions from Top Companies
Master the exact questions asked at Google, Meta, Amazon, and 200+ other companies. From coding challenges to conceptual interviews — we've got you covered.
Interview Coding Questions
1000+ real coding challenges
Practice SQL and Python coding questions with our interactive code editor. Write, run, and validate your solutions in real-time.
SQL Dialects
Python Libraries
Other Languages
Interview Concepts
Master non-coding interview rounds
Prepare for the full interview process with conceptual questions that test your analytical thinking, business acumen, and technical knowledge.
Question Types
Submit your answer and get detailed AI feedback — scored on completeness, accuracy, depth, structure, and practical relevance, with specific improvement suggestions.
Simulate Real Interviews Before the Real Thing
Practice under real conditions with an AI interviewer that tracks your time and delivers detailed feedback on both your code and communication.
Online Assessment
60 min · 2 Qs
Phone Interview
90 min · 2 Qs
Onsite Interview
120 min · 3 Qs
- Choose your role, company, and difficulty — or Quick Start instantly
- Detailed scoring on code quality, correctness, and communication
- Personalized AI review with actionable feedback on your code
Mock Interview Session
Data Analyst · Google · Medium
SMS Confirmations by FB
Find the number of phone numbers that were sent a confirmation SMS text by carrier on August 7, 2020…
Table Schema
- carrierTEXT
- countryTEXT
- dsDATE
- phone_numberBIGINT
- typeTEXT
Build Real Data Projects in Our Cloud Hosted Notebooks
Practice real take-home assignments from top companies. Build your data portfolio and share it directly from your Performance page — no local setup required.
- Real take-home assignments from top tech companies
- Cloud-hosted Python notebooks — no installation needed
- Build and showcase your data portfolio for interviews
- Share your work publicly from your Performance page
Structured Learning Paths for SQL & Python
Go from foundations to interview-ready with our comprehensive free learning paths. Each path covers everything you need for data interviews — with lessons, practice questions, and hands-on projects.
- Comprehensive SQL: foundations to window functions
- Comprehensive Python: pandas, data wrangling, and interview patterns
- 36 lessons and 160+ practice questions per path
- Completely free — no premium required
Comprehensive SQL
Master SQL from foundations to advanced window functions. 6 modules covering everything you need for data analyst interviews.
- 1
SQL Foundations
8 lessons · 4 hr 30 min
- 2
Aggregating & Grouping Data
6 lessons · 3 hr 25 min
- 3
Working with Multiple Tables
8 lessons · 4 hr 5 min
- 4
Subqueries & CTEs
4 lessons · 2 hr 20 min
- 5
Date, Time & Text Functions
5 lessons · 3 hr 20 min
- 6
Window Functions
5 lessons · 2 hr 55 min
AI StrataTools run your code — so you don't run into errors
Validate and optimize your Python and SQL by running it in real environments, delivering reliable results and reducing AI hallucinations.
Transformed Code:
SELECT
customer_id,
order_date,
ROW_NUMBER() OVER (
PARTITION BY customer_id
ORDER BY order_date DESC
) AS rn
FROM orders;Loved by Data Scientists
Join thousands who landed jobs at top tech companies
“StrataScratch has been super helpful. I started with barely being able to finish an easy SQL query to no problem solving most of the medium level in just a few days.”
Kyle
Twitch
“StrataScratch is hands down the best platform if you are preparing for or am working as a data analyst/scientist/engineer. Happy to share that I have gotten an offer from Amazon as a Data Analyst.”
Triman
Amazon
“I really wanted to get into data analytics and data science but never really understood the importance of SQL. The questions are really very realistic and I was asked similar questions in my coding rounds.”
Hemant R
Credit Karma
“SQL is something that is super important and plays a key role in Data Analysis. I used to practice 2-3 SQL problems everyday. The discussion forum and solution with clear understanding cleared my barriers.”
Vikram
Microsoft
“StrataScratch and the community really helped me prep for the interview — I ended up getting the Data Scientist internship!”
Joe
Microsoft
“StrataScratch is awesome! It's the first place I found that allows you to use python in addition to SQL. The Facebook questions were quite similar to the ones that I saw in my interview today.”
Ryan
Level Up Your Data Skills
Free guides, tutorials, and resources from our team
How To Pass Data Interviews for Machine Learning Engineer Roles
How do you get a machine learning engineer job? By passing the interviews, obviously. In this article, we deal with exactly that by detailing how to prepare.
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You Don’t Need to Be a Math Genius for Data Science
Learn the truth about data science interviews and how deep you actually need to go into maths.
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Your Next Interview Is Closer Than You Think
Start practicing with real interview questions today. No credit card required.