I built a browser-based coding education platform as a CS student, here's how

Delfin Obiang — Mon, 13 Apr 2026 14:28:22 +0000

A few months ago I got tired of coding platforms that either spoon-fed you theory or made you watch someone else code. So I built my own, Helix, a browser-based platform where learners write and run real code from lesson one.

Here's what's under the hood:

🐍 Real Python execution in the browser
No backend, no server. Python runs via Pyodide (WebAssembly), so when you hit Run, your code actually executes, not a simulation.

🔐 Auth without a backend
User accounts, sessions, and progress tracking all live in localStorage. Not production-grade for a large app, but for a static site it works surprisingly well and taught me a ton about auth flows.

💳 Stripe on a static site
No Stripe.js, no server. Just Payment Links with a ?upgraded=true success URL that the client detects and upgrades the user's plan in localStorage.

🎨 Pure CSS animations
The DNA double-helix animations across the site? All SMIL SVG, no JavaScript, no libraries. Two anti-phase sine waves with opacity and stroke-width transitions for a depth illusion.

What I learned:

You can build a lot without a backend if you're creative
localStorage auth teaches you why real auth exists
Shipping something real is the best CS education you can get
The platform is live at learnhelix.org, free forever for the first 5 lessons per course.

Would love feedback from this community, what would you build differently? What's missing?

DEV Community: Delfin Obiang

I built a browser-based coding education platform as a CS student, here's how