Site Reliability Engineering (SRE) originated at Google as a discipline for running large-scale production systems. It applies software engineering principles to infrastructure and operations, treating operations work as a software problem and building automated solutions rather than manual processes.
SRE Core Practices
Service Level Objectives (SLOs) are the cornerstone of SRE practice. Rather than pursuing unattainable perfection, SRE teams define measurable reliability targets and use error budgets to balance feature velocity against stability. When the error budget is depleted, the team shifts focus from new features to reliability improvements.
Toil reduction is another fundamental SRE principle. Toil is defined as repetitive, manual, automatable work that scales linearly with service growth. SRE teams are expected to spend no more than 50 percent of their time on toil, investing the remainder in engineering work that permanently reduces operational burden.
Blameless postmortems transform incidents from negative events into learning opportunities. By focusing on systemic causes rather than individual fault, organizations build a culture of transparency that encourages reporting problems early and sharing knowledge about failure modes across the engineering organization.