In this chapter, we were introduced to remote read and remote write endpoints. We learned how the recent remote write strategy using WAL is so important for the global performance and availability of Prometheus. Then, we explored some alternatives for keeping Prometheus local storage under control, while explaining the implications of opting for a long-term storage solution. Finally, we delved into Thanos, exposing some of its design decisions and introducing the complete ecosystem of components, providing practical examples showing how all the different pieces work together. With this, we can now build a long-term storage solution for Prometheus if we need to.