Data Science Educational Resources
StrataScratch is a data science educational platform with over 1,000+ real interview questions from your favorite companies.
Interviews
Case Statement in Python: Best Practices and Alternatives
Mastering case statement in Python with best practices, alternatives, and real-life applications
Nathan Rosidi -
How to Effectively Use the PySpark 'isin' Function
PySpark isin explained with filtering examples using lists, variables, combined columns, and a real interview-style case studyNathan Rosidi -
Creating R Programming Histogram for Data Visualization
Step-by-step guide to creating, customizing, and interpreting R programming histograms using real student performance dataNathan Rosidi -
How to Perform Exploratory Data Analysis in Python (With Example)
Step-by-step Exploratory Data Analysis in Python: From summarizing and visualizing to cleaning and preparing data for modeling.Nathan Rosidi -
How to Define and Use Static Methods in Python
A practical guide to defining and applying static methods in Python using Walmart’s Black Friday dataset to segment customer spending.Nathan Rosidi -
Learn PySpark Joins Easily with This Guide
Master Inner, Left, and Complex Joins in PySpark with Real Interview QuestionsNathan Rosidi -
A Guide to Master Machine Learning Modeling from Scratch
Machine learning modeling is intimidating for beginners. With this article, we’ll make it less complicated and guide you through essential modeling techniques.Nathan Rosidi -
How to Create a Bubble Plot with Python and Matplotlib?
Learn how to build bubble plots in Python with Matplotlib by visualizing multi-dimensional data using real-world interview datasets.Nathan Rosidi -
What Is a Python Abstract Class? When and How to Use It
Learn how abstract classes help structure reusable Python code through a real student data analysis projectNathan Rosidi -
A No-Fluff Guide to Polars vs Pandas
Comparing Pandas and Polars using a real Uber business modelling task — here's who came out faster (and by how much).Nathan Rosidi -
Using Principal Component Analysis in R for Real-World Data
A hands-on guide to using PCA in R with DoorDash data—cleaning, visualising, and modelling compressed dimensions that actually make sense.Nathan Rosidi -
Looping Through Lists in Python: A Comprehensive Tutorial
Learn how to loop through a list in Python using real Uber data, practical techniques, and performance-friendly tips.Nathan Rosidi -