I have multiple services with a job for each. When I deploy a new version of one service, all jobs run.
It could be a very good idea to add an option like "hooks" an array of services/workers/static_sites for each the "kind" will execute. By default, if "hooks" is not specified, it will run every time. So no break with existing option ;)
Take the job : "a-migrations" with "kind"="PRE_DEPLOY" and "hooks"=["a-service"].
If I deploy a new version of "a-service" the "a-migrations" will run before the deploy of "a-service".
If I deploy a new version of "b-service" no jobs will run because any jobs have "hooks" with this service.