Don't Imitate, Understand
by Tony Alicea
Join 367,138 developers worldwide.
Master full-stack, AI-assisted web development and grow from dev → lead → architect.
Meet Your Instructor
Hi, I'm Tony Alicea
Deeply trusted
Hundreds of thousands of developers have chosen to deeply understand
366,783
Enrolled students
109,898
Reviews
25
Years of experience
1
One person I want to help: You.
Tens of Thousands of 5-Star Reviews
How Careers and Lives Were Changed By Understanding
Just spinning my first premium cosmic theme, Galaxy, and super impressed with the DX. The readme, the scripts and the tours :chefskiss: Super good job.
Geoffrey
Patient Since 2020
Cosmic Themes offers more than stunning templates built on a rock-solid Astro foundation—it fosters a vibrant community. With value-added perks like Discord and GitHub invites, Cosmic Themes is a no-brainer for anyone launching a new Astro project.
Connor D
Patient Since 2023
The Blogsmith Pro theme is ridiculously well put together and documented. I learned a ton about Astro engineering by studying it, and I've already used some of the components for my web design clients.
BowTiedFocus
Patient Since 2019
I'm not a front-end dev, but I wanted to rebuild my personal site with Astro. If you're in the same shoes, I can't recommend enough Cosmic Themes. The entire process required exactly one CSS change.
Aniket P
Patient Since 2022
It's the cleanest template standup experience ever! I've never used Astro, but looking at the demo, code, it should be fairly simple pickup on top of my existing React and NextJS experience.
David G
Patient Since 2022
Cosmic Themes provides some of the best Astro themes out there. They are well designed, easy to customize and, most importantly, the team is very responsive concerning support and feature requests. Using their themes allows you to forget about the design and focus on content creation.
Damiano L
Patient Since 2020
Guide AI Safely and Effectively
Become a Full-Stack, AI-Assisted Web Developer
Curiosity and clarity are foundational principles at DIU. An effective AI-assisted developer knows how to guide AI tools safely while understanding the underlying technologies.
// AGENTS.md
You are a senior web developer experienced in semantic, accessible HTML, modern CSS, and JavaScript (ES.Next+).
Learn well
Go Under-the-Hood
Master web development concepts and technologies by diving into how they actually work.
// Learn by understanding how things really work
function greet() {
console.log("I understand why this works!");
}
Learn well
Build Accurate Mental Models
Grasping an accurate mental model let's you architect smartly, debug effectively, and learn new technologies quickly.
let theJavaScriptEngine = 'got it';
let theBrowserRenderingEngine = 'understand it';
let javaScriptFrameworks = 'just other devs’ code';
let LLMs = 'getting great results';