Configuring Jeet zero-downtime deployment for a small app with a persistent database

I'm planning to migrate a small Node.js application to Jeet, which uses a Git-push workflow with automated builds and deployments. The app has a PostgreSQL database and a modest amount of user traffic, so I want to avoid any visible downtime during both the initial migration and subsequent deploys.

From what I understand, Jeet supports zero-downtime deployments through rolling updates or blue-green strategies depending on runtime configuration, but I'm unclear on which strategy applies by default and how to control it. I also need to figure out how to handle the DNS cutover from my current host and how to keep the database in sync during the transition, since Jeet abstracts the underlying cloud provider.

My specific questions:

• Which deployment strategy (rolling vs. blue-green) does Jeet use by default for a containerized Node.js runtime, and is it configurable per project?
• Is there a recommended way to point a custom domain at a Jeet deployment so the DNS switch can be staged and verified before full cutover?
• How should environment variables and database connection strings be managed so old and new instances can share the same database during the overlap period?