Dagger Reflect - The circle from runtime to compile time and back to runtime
summary
Dagger Reflect replaces Dagger’s heavy generated component with a reflection runtime that swaps a 10,000‑line generated component for ~20 lines so local compilation skips expensive annotation processing; a Gradle plugin uses dependency substitution to flip compile/runtime coordinates. Tradeoffs: app startup increases (example 3s → 7s), runtime validation is lazy, error messages are weaker, and some Dagger features aren’t implemented yet. Requires annotation retention set to RUNTIME and minor build changes; real-world usage shows about 19% faster builds for opting‑in developers.
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chapters (15)
- 0:00Introduction and speaker background
- 1:04History of dependency injection
- 2:53The evolution of Dagger
- 4:36Introducing Dagger Reflect
- 6:43How Dagger Reflect works under the hood
- 12:02Project structure and setup
- 18:10How to use Dagger Reflect
- 22:09Dagger Reflect Gradle plugin
- 24:57Current state and limitations
- 26:00Future of Dagger Reflect
- 27:29Usage at SoundCloud
- 28:53Build time improvements and adoption
- 31:23Real-world build performance
- 33:55Trade-offs and developer experience
- 34:17Acknowledgments and closing
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