A URL is like a look behind the curtain. You can hide messy code behind a beautiful interface, but it's hard to hide a messy architecture from the URL.
To me, the URL is where design and engineering truly meet. It’s the purest form of design engineering.
The System of Record
The hyperlink is the actual system of record. If a specific state exists in your app, it should probably have its own URL.
We’ve all had that annoying experience. You’re on a dashboard, you apply three filters, switch to an "Activity" tab, and send the link to a teammate. They click it and land on the generic home screen.
In that moment, collaboration breaks. The context is gone.
The best state is URL state. Whether it’s a search query, a filter, or an open modal: You should always try to persist state in the URL. If it doesn’t have a URL, it effectively doesn't exist for the rest of the world.
Craft is in the Details
In great products, you can tell the URL is treated as an asset. They are basically link products. They are designed for the hyperlink.
Look at Medium or Notion. They append a unique ID to the title (like my-article-5335f89ae). This makes the link readable for humans, but stable for machines. You can rename the post or fix a typo, and the link won’t break.
Or Stripe: They started putting account IDs directly into the URL path. It sounds like a small thing, but for anyone managing multiple accounts, it’s a lifesaver. It turns a generic link into a precise destination.
Even small hacks, like appending .md to a Mintlify URL to see the raw markdown, show that someone was thinking.
These aren't accidents. These are deliberate choices made by people who care about their craft.
A Promise to the User
We talk a lot about "product feel," usually meaning smooth animations. But I think part of that feel is how much you can trust a link.
A good URL is a promise. It promises that what I’m seeing right now is exactly what you’ll see when I send it to you. It allows us to capture a moment on the web and return to it later.
Products are more meaningful when you see the craft behind creation. The URL is one of those crafts.
People look up to those URLs.