# How Dagger Annotation Processing Affected Kotlin Build and Test Performance

DevFeed: [How Dagger Annotation Processing Affected Kotlin Build and Test Performance](<https://devfeed.tech/articles/a-dagger-to-remember-29347.md>)

Original publisher: [Read original article](<https://arturdryomov.dev/posts/a-dagger-to-remember/>)

Author: Artur Dryomov

Published: 2018-04-22T00:00:00Z

Content type: article

Language: en

Sources: [Artur Dryomov](<https://devfeed.tech/sources/artur-dryomov.md>)

Topics: [Dagger](<https://devfeed.tech/topics/dagger.md>), [Kotlin](<https://devfeed.tech/topics/kotlin.md>), [Java](<https://devfeed.tech/topics/java.md>), [Compiler](<https://devfeed.tech/topics/compiler.md>)

Tags: [can](<https://devfeed.tech/tags/can.md>), [compilation](<https://devfeed.tech/tags/compilation.md>), [dagger](<https://devfeed.tech/tags/dagger.md>), [dependency](<https://devfeed.tech/tags/dependency.md>), [development](<https://devfeed.tech/tags/development.md>), [java](<https://devfeed.tech/tags/java.md>), [kotlin](<https://devfeed.tech/tags/kotlin.md>), [kotlin-compiler](<https://devfeed.tech/tags/kotlin-compiler.md>), [productivity](<https://devfeed.tech/tags/productivity.md>), [tests](<https://devfeed.tech/tags/tests.md>), [unit-tests](<https://devfeed.tech/tags/unit-tests.md>)

## AI overview

The article recounts problems with Kotlin annotation processing and incremental compilation in a growing Kotlin and Java project. It describes slow or corrupted builds, later test-performance issues, and an investigation into a Dagger annotation-processing dependency.

## Source excerpt

Story Time! Kotlin and Java annotations have a complicated relationship. This goes from the syntax to the toolchain. Does anybody remember that at the beginning of time Kotlin annotations were placed in square brackets? In 2015 the syntax was changed to the current form. Before that, it was [Inject] instead of @Inject. Yep. The syntax is fine at this point, but kapt (Kotlin annotation processing tool) from the Kotlin toolchain can be... cruel.