How Coinbase is using Relay and GraphQL to enable hypergrowth

By Chris Erickson and Terence Bezman

A little over a year ago, Coinbase completed the migration of our primary mobile application to React Native. During the migration, we realized that our existing approach to data (REST endpoints and a homebuilt REST data fetching library) was not going to keep up with the hypergrowth that we were experiencing as a company.

“Hypergrowth” is an overused buzzword, so let’s clarify what we mean in this context. In the 12 months after we migrated to the React Native app, our API traffic grew by 10x and we increased the number of supported assets by 5x. In the same timeframe, the number of monthly contributors on our core apps tripled to ~300. With these additions came a corresponding increase in new features and experiments, and we don’t see this growth slowing down any time soon (we’re looking to hire another 2,000 across Product, Engineering, and Design this year alone).

To manage this growth, we decided to migrate our applications to GraphQL and Relay. This shift has enabled us to holistically solve some of the biggest challenges that we were facing related to API evolution, nested pagination, and application architecture.

GraphQL was initially proposed as an approach to help with API evolution and request aggregation.

Previously, in order to limit concurrent requests, we would create various endpoints to aggregate data for a particular view (e.g., the Dashboard). However, as features changed, these endpoints kept growing and fields that were no longer used could not…