Site Reliability Engineer

Site Reliability Engineers (SREs) apply software engineering principles to infrastructure and operations problems. Originating at Google, the SRE discipline focuses on creating scalable, reliable systems by treating operations as a software problem. SREs define and manage Service Level Objectives (SLOs), error budgets, and reliability standards that balance innovation velocity with system stability.

SREs write code to automate operational work — building self-healing systems, capacity planning tools, and incident management platforms. They own the production environment and are responsible for availability, latency, performance, and efficiency of critical services. Unlike traditional operations roles, SREs spend at least 50% of their time on engineering work rather than toil.

The role requires deep expertise in distributed systems, networking, and software development. SREs design monitoring and observability systems, implement chaos engineering practices, manage on-call rotations, and lead blameless post-mortems. They influence engineering culture by quantifying reliability and making it a first-class engineering concern.

Key Responsibilities

• Define and manage Service Level Objectives (SLOs), SLIs, and error budgets
• Design and implement monitoring, alerting, and observability systems
• Build automation to eliminate operational toil and manual intervention
• Lead incident response, coordinate resolution, and conduct blameless post-mortems
• Perform capacity planning and ensure systems scale ahead of demand
• Implement chaos engineering practices to test system resilience
• Design for high availability — redundancy, failover, graceful degradation
• Manage on-call rotations and escalation procedures

How to Evaluate a Site Reliability Engineer

• Systems design skills — understanding of distributed systems and failure modes
• Software engineering ability — writing reliable automation and tooling code
• Incident management experience — calm under pressure, structured troubleshooting
• Understanding of SRE principles — SLOs, error budgets, toil reduction
• Linux/networking fundamentals — deep understanding of the operating system and network stack
• Monitoring and observability expertise — designing effective alerting and dashboards

Interview Topics

• SRE principles (SLOs, SLIs, error budgets)
• Distributed systems design and failure modes
• Monitoring and observability architecture
• Incident response and post-mortem processes
• Linux internals and troubleshooting
• Automation and tooling development
• Capacity planning and load testing

Salary & Market Context

SRE salaries in the U.S. range from $110,000 for entry-level to $230,000+ for senior SREs. Principal SREs at major tech companies can earn $250,000-350,000. The role consistently ranks among the highest-paid engineering positions due to its blend of software and infrastructure expertise.

A Day in the Life

An SRE's day starts with checking service health dashboards and reviewing overnight incidents. Morning work might involve analyzing an SLO breach, automating a runbook, or reviewing a design proposal for reliability concerns. Midday includes an incident review meeting or a sync with development teams about upcoming launches and their reliability implications. Afternoons are spent writing code for monitoring tools, running load tests, updating on-call documentation, or working on capacity planning models.