A link that does not move
By João Saraiva
Keeping old versions is easy. The hard part is refusing to change the address, and it turns out to be the constraint that decides most of the rest.
The thing people want from a link is not that it is short. It is that they can send it to fifty people and then get on with their day.
Publishing is a separate act
Updating a site saves a version and changes nothing. The link and every embed keep serving what they served a minute ago; the new version goes live when someone publishes it.
This is the rule that makes the rest work, and it is also the rule that is easiest to lose. When we added the model connector, the tempting shape was: the model writes a new version, the link updates, done. We made it save a draft instead and say so. A link that changes because a model decided it was finished is not a link you would put in an email.
Going back has to be cheap
For a while, archived versions were terminal — once replaced, a version could not go live again. The reasoning was that history should be honest.
It was wrong. Refusing does not preserve history; it means the way back to last week's version is to paste last week's version in again, which produces a new version number pretending to be new work. Now putting an older one live archives the current one in its place. Nothing is copied, and the record stays true.
The link is not the name
Fixing a typo in the title cannot move the address, so they are separate fields with separate rules. And when an address does change, the old one redirects permanently and is never given to anybody else — a link somebody bookmarked must not one day open a stranger's site.
We tested that rule on ourselves this week: the product's noun changed from “tool” to “site”, and the route changed with it. The old route still works and always will. It costs one file.
What it costs
Storage, mostly, which is why free accounts keep the last five versions and paid ones keep all of them. The live version is never dropped, whatever its age — the link has to keep working, and that outranks a plan limit.
It also costs a certain amount of nerve. Every feature that would be simpler if the link could move has to be built the harder way instead.