Code Deployment, Updates, and Environment Workflow
Code deployment workflow
Site Factory uses the Acquia Cloud deployment pipeline: commit to the repository, deploy to dev, then test, then prod. Because all sites in an environment share the same codebase, a code deployment changes the code for every site in that environment at once. What is not automatic is each site's database: schema and configuration updates must be applied per site. Site Factory provides bulk operations to run database updates and clear caches across sites or site groups.
Updates and canaries
A safe pattern is: deploy code to dev, validate on a small canary site, deploy to test, run database updates on a canary in test, then deploy to prod and update sites in batches (for example, by site group). Watch task logs for failures; a failed update on one site should not be hidden by a successful bulk task.
Traps
The biggest trap is believing a code deployment updates all site databases automatically. It does not; each site's update.php must run. Other traps: deploying directly to prod, testing only the factory console rather than a real site, and confusing Composer dependency updates (code) with configuration changes (database). Also note that a module enabled in code is not enabled per site until configuration or an update hook runs.
Rule of thumb
"Deploy code once, update databases many times." Use a canary site and site-group batching; never assume a green deployment means every site's database is current.