Apple WWDC online: "Swift Playground Challenge"

Swift Student Challenge - WWDC20 - Apple Developer

‎Swift Playgrounds on the App Store
for iPad  

391.9 MB

or Mac

‎Xcode on the Mac App Store

node.js + express: best practices

good article:
node.js + express
Production best practices: performance and reliability

expressjs.com/en/advanced/best-practice-performance.html

"This article discusses performance and reliability best practices for Express applications deployed to production.

This topic clearly falls into the “devops” world, spanning both traditional development and operations."