Data Science Educational Resources
StrataScratch is a data science educational platform with over 1,000+ real interview questions from your favorite companies.
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 -
How We Oversaturated the Data Science Job Market
You thought you’d develop ML models and earn serious money. Instead, you’re still looking for a data science job four years later. We’ll look at why it’s like that and what you can do.Nathan 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 -
Why Your ML Job Feels Like a Lie (And What To Do About It)
You thought you’d train models, but now you're writing SQL. This article explains why and how to shift your role toward real machine learning, step by step.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 -
LLM Deep Dive: Practitioner vs. Researcher Path
There are two main approaches to learning LLMs if you already have ML experience. We explore them in this article and give suggestions on what to know.Nathan Rosidi -
Python List Manipulation: Convert Lists to Strings
Convert list to string Python using practical, real-world techniques. Learn clean methods, handle edge cases, and apply them in logging, files, and UIs.Nathan Rosidi -
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 -
T-Test or Z-Test for R: Which Should You Use?
T-test vs. Z-test in crime data analysis: A comprehensive guide to choosing the right statistical method for comparing crime trends, means, and proportionsNathan Rosidi -
11 Data Analytics Projects for Every Level
Data analytics projects are great for practicing and showcasing your analytics skills. Here are project suggestions for every level and resources to use.Nathan Rosidi -