DevOps, Git and CI/CD

Before continuous integration, teams merged weeks of separate work as a project closed and then spent more weeks untangling it. The remedy was to integrate constantly: every change joins a shared line of development and is built and tested automatically within minutes, so conflicts surface while they are still small. Continuous delivery goes further and keeps every passing build ready to release on request; continuous deployment removes the request. DevOps is the broader claim that none of this holds unless development and operations stop throwing work over a wall and start measuring the same outcomes.

The pipeline, stage by stage

• Source control strategy. Trunk-based development keeps branches short and merges daily; feature branches isolate larger work; release branches stabilise a version while the main line moves on. Branch protection makes review and green checks a condition of merging, and Git sits under all of it.
• Build and test. The pipeline compiles or bundles the code, runs automated tests and static checks, and fails loudly. A pipeline that takes an hour, or fails at random, teaches a team to ignore it.
• Package. The output becomes a versioned artefact: a library in a package feed, a binary, or a container image that behaves identically in every environment. Semantic versioning tells consumers what kind of change a new number contains.
• Release. Blue-green deployments switch traffic between two identical environments; canary releases send a small slice of users to the new version first; feature flags separate shipping code from switching it on. Each exists to make a bad release cheap to reverse.
• Observe. Logs, metrics and traces show whether the release behaved, while lead time and time to recover show whether the process itself is getting better.

Tools implement these stages in similar ways. GitHub Actions and Microsoft's Azure Pipelines describe pipelines in YAML kept beside the code; GitLab CI does the same inside its own platform; Jenkins, older and self-hosted, remains common where organisations have years invested in it. Learning one well transfers readily, because the underlying ideas of triggers, jobs, runners, secrets and environments are shared.

Credentials and the career

GitHub's scheme starts with GitHub Foundations, a check of platform familiarity, and continues with separate exams for Actions, Advanced Security, Administration and Copilot. Microsoft's AZ-400 is the heavier credential: an expert-level exam that expects an associate certification first and gives build and release pipelines by far the largest share of its blueprint, beside source control, security planning and instrumentation. Both sit among the operational credentials that carry weight on a developer's CV, because a working pipeline is hard to fake. The usual beginner error is treating DevOps as a job title to acquire rather than practices to adopt; a developer who keeps the team's pipeline fast and trusted is doing DevOps whatever the contract says. Those practices grow out of software engineering practice and depend on the suites built in software testing.