What Does a Site Reliability Engineer (SRE) Do? SLOs and Production Health

A Site Reliability Engineer applies software engineering to operations: defining reliability targets, automating toil, improving incident response, and balancing feature velocity with stability via error budgets.

This guide explains the role in practical terms: what the person actually does, core skills, and when a business should hire for this position - without buzzword fog.

Core responsibilities

Day to day, the role typically covers:

• Define SLIs/SLOs and make reliability measurable.
• Reduce toil with automation and better platform tooling.
• Lead or support incident response and postmortems.
• Improve capacity planning, failover, and chaos/resilience tests.
• Partner with developers on production-ready design.

Skills that matter

Tools change; the underlying competencies stay valuable:

• Strong coding + deep production systems knowledge
• Observability, on-call practices, distributed systems basics
• Performance debugging and capacity intuition
• Blameless culture and clear written communication

When you need this role

High-traffic products, strict uptime promises, complex microservices, or when outages repeatedly damage revenue and trust.

Bottom line

SRE is not “DevOps with a new title.” It is reliability as a product with explicit trade-offs.