Data Science Educational Resources
StrataScratch is a data science educational platform with over 1,000+ real interview questions from your favorite companies.
Interviews

A Comprehensive Step-by-Step Guide to Full Outer Join in SQL
The FULL OUTER JOIN is a very useful but often overlooked SQL join. In this article, we’ll discuss how it works, when to use it, and give practical examples.
Nathan Rosidi -

How to Create a Matplotlib Histogram?
A Matplotlib histogram is a common data visualization in data science. Here, you will learn all the fundamentals of creating and customizing histograms.
Nathan Rosidi -

Introduction to Polars: Everything You Must Know?
Explore how Polars surpasses Pandas in speed and efficiency with a step-by-step breakdown of a real Visa interview question on calculating customer density
Nathan Rosidi -

How to Customize Matplotlib Colors for Better Plots?
Customizing Matplotlib colors is more than just choosing your favorite color for a plot. Colors play a crucial role in communicating your data’s message.
Nathan Rosidi -

Getting Started with PlotlyJS: A Beginner's Guide
Learn how to create interactive charts with PlotlyJS in JavaScript—no setup needed, just code directly in your browser.
Nathan Rosidi -

ML Interviews are Ridiculous And All Over the Place
If you think ML interviews have become crazy lately, you’re not imagining it. They are ridiculous, and we’ll examine why in this ranty article.
Nathan Rosidi -

Data Structures and Algorithms in Python for Beginners
The article will teach you the basics of data structures and algorithms in Python. Arrays, lists, dictionaries, tuples, sets, and queues are all there and more.
Nathan Rosidi -

How to Find the Minimum Value in SQL (with Examples)
Finding the minimum in SQL is easy: just use the MIN() aggregate function. In this article, you will learn how to do it in different real-case scenarios.
Nathan Rosidi -

Easy Guide to Python Hashmaps
What are Python hashmaps, what are the basic operations and advanced techniques, and how to use them in practice? We answer all that and more in this article.
Nathan Rosidi -

Mastering Row Number Handling in SQL Queries
ROW_NUMBER() is one of the essential ranking window functions in SQL. Learn where you can use it and how it works with ORDER BY and PARTITION BY window clauses.
Nathan Rosidi -

Finding Maximum Values in SQL: Aggregation Techniques
MAX() in SQL is a straightforward aggregation method for finding maximum values. Learn here about its syntax and use cases through real interview examples.
Nathan Rosidi -

CONCAT() in SQL: Tips and Techniques for Efficient Queries
CONCAT() in SQL is a data concatenation method. Learn about the tips, techniques, and practical examples of how to use it efficiently in SQL queries.
Nathan Rosidi -