Large scale distributed systems can use round trip time estimates between peers to make intelligent decisions about request routing, data replication, and failure handling. Vivaldi is a distributed algorithm for computing network coordinates for a large set of peers efficiently. In this talk, we motivate the need for network coordinates and introduce the Vivaldi algorithm. We do a brief survey of interesting extensions and related work, both to understand how to use Vivaldi in the wild and to understand the source of errors in it's modeling. Lastly we talk about how Vivaldi is used in the Serf and Consul tools to solve user problems.