- Make sure you either never have trailing slash or always have trailing slash (make sure you have canonical pages and redirects as little as possible)

- Have canonical pages

- Don't trust code you haven't read/don't understand

- Make sure you view changes you make and that they are actually made when you think they are

- Make sure what you want to be rendered on the page is actually rendered

- Write tests

Seems like a bunch of tips for people who are just starting out with web development, to not miss the most obvious problems. How this post is currently on the top of the front page will forever be a question for me. I'm glad more people are discovering SEO and it's importance, but this guide is specifically for one technology and are general tips about development rather than SEO really.

> How this post is currently on the top of the front page will forever be a question for me.

OP/Author here, to me too trust me

Yes, sites require a bit of JS (added some client side feature recently). Hope the summary other commenter gave you helped

Turning off JS revealed practically the same website, but go on.