CO2ntra is campaigning for the reduction in CO2 emissions, with the motto „enough talk, let’s act – and act now“. Users can use the app and website to calculate their footprint and support climate-friendly projects to reduce emissions. Kontext-e supported our local partner from Dresden in determining the requirements. A scalable architecture was derived based on this, which was then implemented using a technology stack consisting of JavaScript for the frontends and Java for the backend.