The loop it is built around
Describe what you want changed. Watch it land in the editor, with the diff visible rather than applied behind your back. Preview it running. Then publish it and attach a custom domain, all from the same window.
The gap this closes is not writing code, it is everything either side of writing code. Most of the friction in shipping a small site is in the ten context switches around the edit.
How it is put together
Electron with a strict split: every capability lives in the main process, exposed through one typed bridge to the interface. The renderer cannot reach the system directly, which keeps the surface small and the boundaries honest.
Monaco for editing, a real terminal through the native Windows console API rather than a shim, and a small built-in static server so projects with no build step still preview properly.