Enforce types at runtime
APIs all the way down Frontend and backend developers these days have to deal with many external APIs, usually REST APIs. Fetching data is easy, but making sure the data is valid and conforms to an expected schema can get messy.
Foreign APIs can change over time or simply deliver rubbish, especially on Friday afternoons or at midnight during a lunar eclipse.
It is therefore important to detect issues quickly and reliably to prevent error propagation to the deeper parts of our software architecture.