Vercel: separate what builds, what a preview reads and what a rollback restores

What builds

By default a push creates a deployment for every connected project in a monorepo. Vercel can skip a project when its source, an internal dependency or a lockfile change affecting it has not changed, provided the repository uses workspaces with uniquely named packages and declared dependencies. The older route is the ignored build step: a command that exits with 1 to continue or 0 to abort. An aborted build is marked cancelled and still counts toward deployment and concurrency limits, so the built-in skipping is better where it applies.

• Built-in skipping needs declared dependencies and unique names.
• The ignored build step is the fallback and has a cost in limits.

What a preview reads

A preview is created for pushes to non-production branches and for pull requests, and is built with the Preview environment's values. A changed value applies only to new deployments, so an older preview keeps what it was built with. The first deployment of a new project is always a production deployment, regardless of branch, which surprises teams that expect a preview first.

What a rollback restores

An instant rollback points production domains at an earlier deployment without rebuilding it. Environment variables are not changed, so a value edited since then stays edited. After a rollback, automatic assignment of production domains is turned off, so new pushes to the production branch do not go live until a deployment is promoted again; remember to undo the rollback.

Priced routes

A Next.js build that fails on Vercel while it works locally is covered by the existing £149 fixed job. Automatic previews for every pull request begin at £695, a rollback step rehearsed on staging begins at £595, and making monorepo CI run only affected packages begins at £795; each is untested, covers one repository or service, and is paid after you sign off. We do not create accounts or buy plans. Send the redacted first error or how deploys work today, with no credentials or code in a first message.