APIs vs Data contracts

APIs and data contracts have a lot in common, and APIs were part of the inspiration behind data contracts when I was coming up with the idea a few years back. The both provide the interface (see my post from a couple of weeks ago on the importance of interfaces), they both set expectations for the user (the structure, semantics, SLOs, and so on), and they both allow for integrations with other services, tools, etc.

The main difference is the type of interface provided through a data contract. This is a dataset, typically a table in a data warehouse but could also be a stream of data through Kafka, Pub/Sub, etc.

And because it’s a dataset we also use the data contract to manage that data in line with our relevant policies and regulations (access controls, GDPR, etc), hopefully automating them as much as we can.