What are the methods to easily maintain mocked responses that evolve over time?

What are the different options to maintain complex json responses from backend services over time as they evolve?

For example, if I have a complex response that needs many saved version of the json (using fixtures in Cypress... for example). If the response evolves and changes, I will need to update all those json files.

Using mocked json seems like an easy way to set one test data, but I am afraid that over time, I end up with many outdated versions of the response or in need to do tedious updates to the many files when changes happen.