I remember the first time I used a sophisticated online coding playground like codedamn. It wasn't just a single-file snippet editor. It was a full, containerized environment where I could:
- Spin up an entire React or Next.js app with preview.
- Run a Java program or a Go code.
- Install dependencies, run builds, and see live output—all in the browser.
The experience was incredibly fast, smooth, and reliable. I was blown away. And immediately, the engineer in me asked: "How on earth is this built?"
This blog is the story of my deep dive into that question. It's not a tutorial for a finished product, but a research log of the architectural problems I identified and the potential solutions I explored to build such a system at scale.