The success of Cloud computing is the result of a wide adoption by stakeholders to offload their IT services in remote data centers. This mutation in the management of infrastructures has also shade the light on the cost of software services, both from financial and environmental perspectives. While the cloud offers a potentially infinite amount of computing resources, cloud customers are getting increasingly concerned about the carbon footprint of their software services and are considering optimisations of their applications that can contribute to reduce their impact on the environment. On the other side, cloud operators are also increasingly considering optimisations to make a better usage of their computing resources, thus going beyond the standard PUE indicator to deliver high quality of service. During this presentation, I will overview some of the contributions that our team and our colleagues have delivered to deliver more sustainable software services by considering the energy as a first class entity to optimize.