Data Science Educational Resources
StrataScratch is a data science educational platform with over 1,000+ real interview questions from your favorite companies.
Interviews
PySpark SQL Functions: Boost Big Data Processing with SQL
Leverage PySpark SQL Functions to efficiently process large datasets and accelerate your data analysis with scalable, SQL-powered solutions.
Nathan Rosidi -
Counting Distinct Values in SQL: Tips and Examples
Using SQL COUNT(DISTINCT) is an easy way to count distinct values in SQL. However, it has its own quirks, which we’ll explain (with examples) in this article.Nathan Rosidi -
Commonly Asked Data Structure Interview Questions
Data structure interview questions are a big part of interviews for many data roles. To answer them, you should know the data structures we’ll cover here.Nathan Rosidi -
The Fundamentals of Structuring Data
Mastering data structuring is key to efficiently organizing, accessing and make sense of the vast amounts of data we interact with on a daily basis.Nathan Rosidi -
How Do You Perform SQL LIKE Queries for Pattern Matching?
The LIKE SQL query allows you to perform a pattern-matching search of your text data. Learn how to use it and add wildcards for increased flexibility.Nathan Rosidi -
What is Big O Notation? (+ Cheat Sheet)
Big O Notation helps developers predict how an algorithm's performance scales with input size, guiding them to choose the most efficient solution.Nathan Rosidi -
Utilizing DENSE_RANK for Data Deduplication in SQL
Data deduplication in SQL can be done in several ways. Using DENSE_RANK() is one. Today, we’ll talk about using this function to improve your data’s quality.Nathan Rosidi -
How to Determine Python String Length?
Discover the simple yet powerful tools Python offers to measure string length effortlessly, enhancing your coding efficiency and data manipulation skills.Nathan Rosidi -
From Arrays to Lists: Converting Numpy Arrays with Python
Learn the essential methods for converting NumPy arrays to Python lists, enhancing your data handling skills in Python with practical examples and applications.Nathan Rosidi -
PySpark GroupBy Guide: Super Simple Way to Group Data
Master efficient data grouping techniques with PySpark GroupBy for optimized data analysis.Nathan Rosidi -
Adding and Removing List Elements with Python
Explore the versatile techniques of adding and removing elements in Python lists to enhance data manipulation and streamline your coding workflow.Nathan Rosidi -
SQL PARTITION BY: Advanced Analytical Insights
SQL PARTITION BY makes SQL window functions – already a powerful analytical tool – even more suitable for advanced analytical insights from your data.Nathan Rosidi -