I have been looking around and cant seem to find a guide to code management and versioning. Is there a guide for best practices or how to work in a CI/CD framework to be able to deploy new/updated code without breaking existing code?

Can you explain your use case? CI/Cd in general or related to Airbyte?

General: There will be transformation and maybe even extract code that will change over time. (Adding new columns, new tables, change of business logic for calculating metrics, etc..) this we would want to build and test in lower environments then have deployment (prefer automated with integrated testing) to move the new code from lower environments (dev) to higher (prod). With Airbyte...which i am just learning...seems all the transformation logic is done in dbt and has a separate git repo. So managing that might work. What happens when a source changes, how does airbyte handle that or will it just fail?