Ask HN: Fastest/easiest way of building a web application in 2020?

I'm curious what people consider the fastest/easiest way to build a full-stack SaaS app in 2020.

Assume the following:

- Can be picked up by almost anyone (assume basic HTM/CSS/JS understanding), doesn't require any deep CS understanding.

-Has full-stack capabilities, not just front-end

- Is open source and can be deployed anywhere

- Is complex enough to rule our no code solutions like Bubble or Webflow