Deploy

Deployment (to deploy) is the process of taking a new version of an application, website or service out of the development environment and putting it onto a target server — usually production — where it begins handling real traffic. A deploy is more than copying files: it typically includes installing dependencies, running database migrations, rebuilding caches and reloading long-running processes.

How a deployment works

Modern teams automate the whole path inside a CI/CD pipeline. A typical run looks like this:

1. Build — the pipeline checks out the code, installs dependencies, compiles frontend assets and produces an artifact such as a Docker image or a versioned archive.
2. Automated tests — unit and integration suites act as a gate; a red build never reaches production.
3. Ship — the artifact is delivered to the server via container registry, rsync, or a fresh release directory.
4. Post-deploy steps — migrations, cache warm-up, worker restarts and a health check confirming the new version responds correctly.

Deployment strategies

• Rolling — instances are replaced gradually, so the service never goes fully offline.
• Blue-green — two identical environments; traffic flips to the new one only after verification, and rollback is an instant flip back.
• Canary — the new build first serves a small percentage of users while metrics are watched.
• Releases with a symlink — every deploy lands in its own timestamped directory and a symlink points to the active one, making rollback a one-second operation.

Deployment in practice

The right mechanism depends on the infrastructure. On shared hosting a deploy may be a Git pull or an SFTP upload, while a VPS or container cluster justifies fully automated pipelines with health checks and automatic rollback. Two habits pay off regardless of scale: deploy small changes often, because a small diff is far easier to debug when something breaks, and keep a staging environment that mirrors production. Every deployment should be repeatable, reversible and traceable to an exact commit in version control.