> For performance reasons alone, you definitely want to host as much as possible on the same domain.
It used to be the opposite. Browsers limit the amount of concurrent requests to a domain. A way to circumvent that was to load your resources from a.example.com, b.example.com, c.example.com etc. Paying some time for extra dns resolves I guess, but could then load many more resources at the same time.
Not as relevant anymore, with http2 that allows sharing connections, and more common to bundle files.
Years ago I had terrible DNS service from my ISP, enough to make my DSL sometimes underperform dialup. About 1 in 20 DNS lookups would hang for many seconds so it was inevitable that any web site that pulled content from multiple domains would hang up for a long time when loading. Minimizing DNS lookups was necessary to get decent performance for me back then.
It used to be the opposite. Browsers limit the amount of concurrent requests to a domain. A way to circumvent that was to load your resources from a.example.com, b.example.com, c.example.com etc. Paying some time for extra dns resolves I guess, but could then load many more resources at the same time.
Not as relevant anymore, with http2 that allows sharing connections, and more common to bundle files.