As software engineers it is sometimes too easy to forget the impact that our code has on the environment. We build for changeability, speed and hopefully quality, but we forget about sustainability. The time to act is now. It is time for us to take responsibility and to write more sustainable tech. In this talk I will talk about things we can do to write more energy efficient code. I will also talk about hosting your code more sustainably. And last but not least… I will share the software architecture needed to build greener applications using Symfony Messenger.