In terms of referral bonus amounts, my company (PagerDuty, YC S10) offers between $5K and $20K depending on the role and priority. This includes engineering roles as well. The cool thing is we pay out for external referrals. Anyone can send a referral our way and if a hire is made, you'll get paid the full amount. Not too many companies do that :)
It's less for other roles.
(Source: 10 years in the valley. Made several hires, set recruiting processes at my last company, and now I run a bootcamp for technical interview prep: http://InterviewKickstart.com)
I've made it a point to refer not a single person again because I'm tired of my and my employer's time being pissed away, when we can just dispense with the bullshit and get back to doing real work.
has anyone ever actually been paid out for a referral?