Contract Launches` in Apollo Studio provide better visibility into the lifecycle of contract schemas and help developers understand which contracts launched from a given source variant. When publishing updates to a source variant, it triggers downstream launches for any contract built from that source, with each launch resulting in either a successful core schema or failed contract schema output. The system allows users to review changes made to their graph by checking the `contracts changelog` and provides a link to `Launch Sequence` to debug failed launches. Additionally, a `changelog` page shows any types or fields from the contract schema that have been added, removed, or modified.