DevOps and SRE Practices
What is DevOps?
DevOps is a set of practices, tools, and cultural philosophies that aim to shorten the Software Delivery Lifecycle (SDLC) while maintaining high quality and stability.
Core Idea
Break down silos between Development and Operations so teams can work together to build, test, release, and run software efficiently.
Silos mean people or teams working separately and not talking to each other.
DevOps Focus Areas
- Automation of repetitive tasks
- Continuous Integration and Continuous Delivery (CI/CD)
- Infrastructure consistency
- Collaboration between teams
- Fast feedback loops
Typical DevOps Responsibilities
- Build and maintain CI/CD pipelines
- Manage infrastructure using code
- Package and deploy applications
- Improve deployment speed and reliability
- Support developers with tooling and automation
What is Site Reliability Engineering (SRE)?
Site Reliability Engineering (SRE) is a discipline that applies software engineering principles to operational and reliability challenges.
Core Idea
Treat operations as a software problem and improve system reliability through engineering and automation.
SRE Focus Areas
- Reliability and availability
- Monitoring and alerting
- Incident response and postmortems
- Capacity planning
- Risk management through error budgets
Typical SRE Responsibilities
- Define and measure reliability using SLIs, SLOs, and SLAs
- Design monitoring and alerting systems
- Respond to and analyze production incidents
- Automate operational tasks
- Improve system resilience and scalability
DevOps vs SRE (High-Level Comparison)
| Aspect | DevOps | SRE |
|---|---|---|
| Primary goal | Speed and delivery | Reliability and stability |
| Focus | CI/CD, automation, platforms | SLIs/SLOs, monitoring, incidents |
| Common tools | Git, CI/CD, containers, IaC | Monitoring, alerting, automation |
In many organizations, DevOps and SRE roles share similar tools but differ in priorities and success metrics.
Overview
DevOps and Site Reliability Engineering (SRE) are both about taking software from code to a running, reliable service. They focus on how changes are made, how applications are deployed, how systems run at scale, and how issues are detected and fixed in production. To do this effectively, engineers need a strong foundation in a few core areas: Git for tracking and managing changes, GitOps and CI/CD for automating builds and deployments, containers for keeping applications consistent across environments, Kubernetes for running and scaling those applications, and observability for understanding what is happening inside a system. These fundamentals form the base knowledge for anyone starting a journey into DevOps or SRE.
The sections below cover the core technical foundations shared by both DevOps and SRE roles.
Git Fundamentals
Git is the foundation of modern DevOps and SRE workflows.
Key Concepts
- Git basics: clone, commit, branch, merge, rebase
- Common workflows: feature branches, trunk-based development
- Git repositories as the single source of truth
GitOps and CI/CD
- Declarative infrastructure stored in Git
- Pull-request based changes
- Automated pipelines for build, test, and deploy
- Rollbacks using Git history
Containerization
Containers provide environment consistency and portability.
Core Concepts
- Problems containers solve (dependency and environment drift)
- Difference between images and containers
- Container lifecycle
Practical Fundamentals
- Writing basic Dockerfiles
- Building and tagging images
- Running and debugging containers
- Using container registries
Kubernetes
Kubernetes is the standard orchestration platform for containerized workloads.
Key Concepts
- Cluster architecture (control plane and worker nodes)
- Core objects: Pods, Deployments, Services
- Configuration management: ConfigMaps and Secrets
- Namespaces for isolation
Practical Engineering Focus
- Stateless vs stateful workloads
- Scaling and self-healing
- Rolling updates and rollbacks
- Basic security concepts (RBAC, service accounts)
Observability
Observability helps engineers understand what is happening inside a system and why.
Three Pillars of Observability
- Metrics – system health and performance
- Logs – events and debugging context
- Traces – request flow across services
Key Concepts
- Golden signals: latency, traffic, errors, saturation
- Monitoring vs alerting
- Symptoms vs root causes
- Actionable alerts
SRE-Specific Reliability Concepts
- Service Level Indicators (SLIs)
- Service Level Objectives (SLOs)
- Service Level Agreements (SLAs)
- Error budgets
- Blameless postmortems