Separating users by subdomain leaks information. An observer can trivially see your DNS queries but not which repository you access over https or ssh. There is

Separating users by subdomain leaks information. An observer can trivially see your DNS queries but not which repository you access over https or ssh. There is also little benefit in it. If the subdomains only point to the same servers then the same level of traffic will still take them all down, but if different subdomains point to different servers then it makes attacks easier because the attacker only needs enough resources to overwhelm 5% of the servers instead of all of them.