Yelp's engineering isn't likely much more than ~150 people (I worked there ~2 years ago, maybe has grown since then but honestly, given their revenue situation even then, likely not by much). The mix there is just like most companies; you've got dedicated teams for each of their apps (which includes Android, iOS, web, business-facing, etc), you've got API teams, back office teams working on moving data around and business analytics, a very secretive abuse management team, IT, etc. Yelp also, given their age, wasn't (at some point) running their primary workloads in the cloud; they had (have?) a colo DC in San Francisco that hosted a ton of stuff, so there were people dedicated to that hardware. There was some movement to get rid of this as I remember.
Surprisingly, or hopefully not, the vast majority of the company is more directly revenue generating; sales and customer acquisition. Its spread very globally; at least as of a few years ago, the SF HQ didn't house any sales people, though I think they had an office in Oakland which did.
Point being, I always got the impression that their engineering team was very "right sized" given their revenue and product scope.
Surprisingly, or hopefully not, the vast majority of the company is more directly revenue generating; sales and customer acquisition. Its spread very globally; at least as of a few years ago, the SF HQ didn't house any sales people, though I think they had an office in Oakland which did.
Point being, I always got the impression that their engineering team was very "right sized" given their revenue and product scope.