The text discusses the challenges and solutions for implementing API versioning at the code level, with a specific focus on practices at Clearbit using Ruby and Sinatra. It highlights the complexity often involved, such as conditional statements cluttering the codebase, and proposes a date-based versioning system that uses the date of the first API call as a version reference, allowing clients to upgrade via account settings. For route-based changes, new routes are created and mounted in reverse chronological order, facilitating straightforward testing and easy removal of deprecated versions. Additionally, the concept of a 'serializer' is used to manage changes to data returned by the API, with major changes requiring new resources and minor changes handled by conditional logic. The approach aims to balance simplicity with the DRY principle, and the author invites feedback on best practices, noting that the system is still evolving.