I'm just curious

Which web server/database/backend things do Scratch use? Revealing this probably wouldn't cause any security issues

I know the older parts of the site use Django, and I believe the newer parts are Node, but I'm not 100% sure.

jvvg wrote:

(#2)
I know the older parts of the site use Django, and I believe the newer parts are Node, but I'm not 100% sure.

That is correct. From the scratch-www README file:

Core technologies

Significant core technologies this codebase uses include:

Development technologies

• Node
  
• Webpack
  
• React
  
• Redux
  
• Sass

That's the frontend, though; if I'm understanding correctly, OP is interested in the background stuff.