No builder author can be truly omniscient, and whoever created yours surely was no exception!
Environment variables are a common way to configure various buildpacks at build-time.
Supply and persist data from build containers with arbitrary volume mounts.
Simplify your pack configuration.
Customize your build with a bit of shell script.
Share layers between builds with a cache image.
Tell pack where you want your application image to be saved.
Buildpacks can define multiple processes for an application image. Specify which process should be the default.