Handling External Service Requests in Elixir

In this content, Ayrat Badykov steps away from his usual focus on cryptocurrency topics to address a challenge familiar to many software engineers: handling interactions with external services efficiently in their code. Using Elixir, he outlines a method for writing code that is both maintainable and testable with ease. The article walks through an example of synchronizing transactions on the Ethereum blockchain and highlights common problems encountered such as complex logic, error handling, and testing. Badykov introduces the Saga design pattern and its Elixir implementation, sage, to solve some of these issues. For testing, he recommends using the mox library, which allows for creating mock clients. To address unstructured responses from external services, he suggests using the parameter library to validate responses, thus ensuring reliability against unexpected API changes. The content concludes by emphasizing the benefits of these tools and patterns in improving code robustness, maintainability, and testability when working with external services in Elixir.