After 4 years of building applications and following excellent developers on Twitter, these are the principles I have developed. Studying open source projects taught me what actually works in production. I will add real examples as I collect them.

URLs should be beautiful and predictable

URLs should read like poetry: clean, intuitive, and instantly understood. Use lowercase paths like /products/reviews, not /Products/Reviews.

When users see ?sort=asc, ?sort=desc should also exist.

You might not need SSR, SSG, PPR, ISR, WTF??

Most of the time, a SPA with a backend server works extremely well. All those fancy SSR, SSG, and PPR buzzwords are often overkill.

URLs should store states

Your app state should survive refreshes. Put filters, sorts, and selections in the URL. Users love sharing links that actually work.

Instead of storing filter state in React state:

const [filter, setFilter] = useState("active");

Put it in the URL: /tasks?status=active&sort=date&page=2

Why? A refresh gives the same results. Users can bookmark specific views. Sharing /products?category=shoes&color=red&size=10 actually works. The back button navigates filter history. You avoid the usual “why did my filters reset?” frustration.

Animations should be subtle, not loud

Animations should whisper, not scream. A 200ms opacity fade beats a 2-second bounce any day. Subtle transitions guide attention without hijacking it.

Flashy animations cause layout shifts and cognitive overload. A spinning loading indicator is rarely impressive; it just makes users wait longer. Keep motion minimal, purposeful, and performance-conscious. Often, the best animation is no animation.