Design APIs to minimise the number of requests and the size of the data transferred in each response.
Hard to implement
8 High impact score
A REST endpoint typically returns a fixed shape of data whether or not the client needs all of it, a client that only wants a product’s name and price still receives the full record. GraphQL lets the client specify exactly which fields it needs across however many resources in a single request, which cuts both the number of round trips and the volume of data sent over the wire compared with calling several REST endpoints separately.
This is a genuine “sustainable design pattern” in its own right, not just a performance nicety: this pattern has moved from niche to mainstream over the last few years as major commerce and CMS platforms (Optimizely/Episerver’s Commerce Core among them) have adopted GraphQL as a first-class option alongside REST.
It’s a bigger lift than most of the other items in this guideline set, since it usually means introducing a GraphQL layer rather than a config change, so it’s listed as a design decision to weigh up for new APIs or major replatforming work, rather than a universal retrofit.