Once upon a time, our implementation partner performed a major update on their API. Boom! This update wrecked our end-to-end tests, and it took us 172 hours to fix them. Our software often depends on another team’s API, thereby making our tests fragile. Test data may go missing. The API might be slow, making our tests flaky. An endpoint’s response schema might change, causing some features to break. All of this can lead us to waste a tonne of time analyzing tests that break for no fault of ours. But there is a solution to this problem - consumer driven contract testing. This talk will detail how you can test your application in a manner that is robust to API changes in a partner team. We will give you an overview of how we are tackling this problem using automated API tests, schema validation and by hosting API test doubles on a mock server. Once you’ve done all this, you and your implementation partner can work together happily ever after.