Better Practices of Site Reliability Engineering

Hire only coders.
Have an SLA for your service.
Measure and report performance against the SLA.
Use Error Budgets and gate launches on them.
Have a common staffing pool for SRE and Developers.
Have excess Ops work overflow to the Dev team.
Cap SRE operational load at 50 percent.
Share 5 percent of Ops work with the Dev team.
Oncall teams should have at least eight people at one location, or six people at each of multiple locations.
Aim for a maximum of two events per oncall shift.
Do a postmortem for every event.
Postmortems are blameless and focus on process and technology, not people.

SLI = [Good events / Valid events] x 100

Reliability level	Per year	Per quarter	Per 30 days
90%	36.5 days	9 days	3 days
95%	18.25 days	4.5 days	1.5 days
99%	3.65 days	21.6 hours	7.2 hours
99.5%	1.83 days	10.8 hours	3.6 hours
99.9%	8.76 hours	2.16 hours	43.2 minutes
99.95%	4.38 hours	1.08 hours	21.6 minutes
99.99%	52.6 minutes	12.96 minutes	4.32 minutes
99.999%	5.26 minutes	1.30 minutes	25.9 seconds