We present Sourcey, a new data center network architecture with extremely simple switches. Sourcey switches have no CPUs, no software, no forwarding tables, no state, and require no switch configuration. Sourcey pushes all control plane functions to servers. A Sourcey switch supports only source-based routing. Each packet contains a path through the network. At each hop, a Sourcey switch pops the top label on the path stack and uses the label value as the switch output port number. The major technical challenge for Sourcey is to discover and monitor the network with server-only mechanisms. We design novel algorithms that use only end-to-end measurements to efficiently discover network topology and detect failures. Sourcey explores an extreme point in the design space. It advances the concept of software-defined networking by pushing almost all network functionality to servers and making switches much simpler than before, even simpler than OpenFlow switches. It is a thought experiment to show that it is possible to build a simple data center network and seeks to raise discussion in the community on whether or not current approaches to building data center networks warrant the complexity.