For years, our iOS codebase relied on Sourcery to generate mock files for testing. It worked, until we were maintaining over a thousand generated files that bloated the repo. When Apple released Swift Macros, we saw a way out.

This talk is the story of SwiftMockKit, an internal library that generates mocks at compile time with a single annotation, and how we're migrating a large fintech codebase off file-based generation. Our first batch swapped 14 protocols in a single PR; along the way we've deleted nearly 91,000 lines of committed mock boilerplate.

You will learn:
- Why file-based mock generation stops scaling, and the pain signals to watch for in your own codebase
- A migration path from Sourcery
- Where macros fall short: the protocols we couldn't handle and the compile-time costs we measured

If your test suite depends on generated mocks, you'll leave knowing exactly how to delete them.