The present disclosure relates to processing write requests across a plurality of data sources. According to one embodiment, an example method includes determining a navigable path of nodes accessed to satisfy a write request in a graph projection of an application programming interface (API). An API service generates a plurality of subqueries, each subqueries being associated with a node in the navigable path. While traversing the navigable path to execute the write request, the API service identifies one or more nodes in the navigable path sharing an association with a data repository associated with the current node and upon which execution of a write operation associated with the current node depends. The API service coalesces a set of subqueries associated with the current node and the identified one or more nodes into a single subquery and executes the single subquery.