Where to find updated developer documentation, please?

Dear Users,

does anyone know where I can find and updated developer documentation?
It seems that all recent links on docs.nextcloud.com are dead?!

(file not found)

(file not found)

(file not found)

The only one that seems to work is v14 and older.
Am I the only one having this issue or is this software really documented that bad?

Thanks and regards.

Documentation is published to docs.nextcloud.com. Perhaps the server has an outage.