I know a couple. The answer is simple: Money. Facebook pays way above what other tech companies pay (a 6 year of experience senior engineer in Menlo Park can easily make 600k/year). There is also a sense of pride coming from back in the days when Facebook was still seen as a very exclusive and wonderful place to work at.
Not being facetious, but what to the devs do all day to earn that?
Their core functionality, Find a Friend, is pathetically limited and naive. Why can't I search for ( cohort of near my age who went to my school ) or ( everyone called Bob who is one or two hops from Alice and lives in Bigville )?
Or even search a friend list by some criteria instead of scrolling through 1200 names.
> Why can't I search for ( cohort of near my age who went to my school ) or ( everyone called Bob who is one or two hops from Alice and lives in Bigville )?
They had this feature a couple years ago. It was called Graph Search and did exactly what you're suggesting (and even more impressive than that). They shut it down fairly quickly because it was a huge privacy and security issue as well as an incredibly abusive feature at their scale.
Building products in a system as complex as FB is not as straightforward as adding features just because you can or have the talent to do so.
Most devs in bigTechs micro optimize very little things (ie, cogs in the machine). It makes sense only at a scale where those micro-optimization can pay for themselves.
I'm not sure how you stay sane working on those micro-issues though.
