Apollo Federation is an open-source approach to application architecture created by Apollo, aiming to solve the problems associated with monolithic graphs as they grow and evolve. It's based on a design principle called separation of concerns, dividing the graph into smaller subgraphs that address specific functions or purposes. This modularization makes it easier for teams to work together, reduces breaking changes, and improves development speed. The architecture consists of subgraphs and a gateway that combines them using a supergraph schema. Apollo Federation benefits individual developers by organizing their code, making it easier to navigate and scale, while teams can increase productivity and collaboration. Client-side developers remain unaffected, with only one endpoint to access the data they need. To get started, check out the Apollo Federation specification, quickstart guide, and other resources provided.