Flow design lifecycle
Drafts have a set lifecycle. They are created, built, and tested in Flow Designer, published to the Catalog and finally deployed through the Deployment Wizard or the CLI as flow deployments.
Flows created with Flow Designer have a set lifecycle. You start with creating a draft in Flow Designer. You can start from scratch, but you can also open an existing flow definition from the catalog, or a ReadyFlow from the gallery to use it as a template for your draft. You then build up your flow on the flow design canvas by adding and configuring components, establishing relationships between them, creating services, and so on. Whenever you feel the need, you can start a test session to verify what you have built so far. Starting a test session commissions a NiFi sandbox allowing you to test and simultaneously update your draft. Once you deem your draft to be production ready, you publish it to the catalog as a flow definition. Once published, you can keep updating your draft and publish it as a new version of your flow definition. Should this draft be lost, for example because the workspace holding it got deleted, you can always create a new one from the flow definition you have published the catalog.