Heroku


 * Platform as a Service

.profile.d scripts

 * config file to specify stable env variable such as $PATH
 * scripts execute order isn't defined so scripts must be independent from it
 * node.js buildpack use this to specify PATH to node_modules executable scripts
 * $BUILD_DIR /.profile.d
 * $HOME will be the slug path

maintenance mode

 * used to disable app temporary

Buildpack

 * list of official buildpack
 * list of 3rd party buildpack
 * API spec
 * detect
 * compile
 * release
 * node.js buildpack
 * uses compiled node.js executable
 * mruby buildpack using compiled mruby binary
 * C build pack using make in compile