The initial prototype did use React, but the overhead in certain cases soon became an issue. It got replaced by a custom virtual dom implementation (coincidentally quite similar to Atom's Etch), but debugging complex updates remained an issue. Eventually, it ended up in a place quite similar to vscode: no frameworks and a handful of "core components" (eg: a virtualized list view)
The initial prototype did use React, but the overhead in certain cases soon became an issue. It got replaced by a custom virtual dom implementation (coincidentally quite similar to Atom's Etch), but debugging complex updates remained an issue. Eventually, it ended up in a place quite similar to vscode: no frameworks and a handful of "core components" (eg: a virtualized list view)