serg as discussed before, this doesn't really make sense for buildbot.mariadb.org, since many builders are:
1. using docker, no webserving or other public service running on the machines
2. build workers vary wildly in configuration between computing power, storage and network performance
3. actual machines are either owned or donated, behind firewalls or not and with unlimited resources or not
4. in the future we might scale builders, aka. run some extra machines temporarily in the cloud just for the duration of high activity period, say before a GA release

The only feasible way is still having a single download location. For now, buildbot.mariadb.org artefacts are available at:
ci.mariadb.org and from within the build logs:
https://buildbot.mariadb.org/#/builders/11/builds/637

Click on Step 11 -> Download. For now, the server can handle it, but yes, in the future this might not be desirable, however, this being hosted on DigitalOcean, I can easily split the asset serving to a different machine or just a Storage Bucket Space with static CDN serving that should scale for any load.

If you're satisfied with this resolution, you can close this issue.