- Dependency injection with a container - Dependency management with Composer We have : Doctrine, Propel, Twig, Assetic, Monolog, Buzz, Bundles... First way of improving an application performance is to update dependencies. Updating dependencies is natural for an application to stay performant. Example : upgrading PHP from 5.3 to 5.4 makes you at least a 20% difference in performance. If you can't update your dependencies, your application has a big problem.