Sorry if this is inappropriate context but the subject got me looking at the Cloudflare job board and there are some interesting positions and I'm wondering if it's appropriate to apply to multiple positions at once, or is better to apply to the 'favorite' in the case that there are more than one that interests one?
It's definitely appropriate to apply to multiple job posts at once. Jobs are reviewed by different hiring managers who look at your application independent of other jobs you may have applied.
HM here, don't apply to every job on a website (spamming is obvious) but definitely go for any you're actually interested in. Different recruiters often own different postings and some may be more responsive/amenable than others.