A large portion of an Android app’s build time can consist of Dagger annotation processing, and most developers agree that productivity is important, so we decided to experiment to see if we could save time when compiling the SoundCloud Android app. This blog post covers how we used Dagger Reflect to save developer time with minimal changes to our codebase.
Part of a build engineer’s role is to speed up builds. Improving build performance and avoiding work with caching is one way to achieve this, but another tool in the build engineer’s belt is that of disallowing slow builds. This is part two in a series about solving Gradle remote build cache misses.
Until recently, one of the top technical risks facing SoundCloud’s Android team was increasing build times. Our engineering leadership was well aware of the problem, and it was highlighted in our company’s quarterly goals and objectives as modularization. Faster build times means more productive developers. More productive developers are happier and can iterate on products more quickly.
Modularization is key to decreasing build times, but avoiding work is another important part of the puzzle, and build caching is one way to avoid that work. Gradle, our tool for building Android, has a local file system cache that reuses outputs of previously performed tasks. We have been using the Gradle remote build cache in order to save our developers’ time. It helps us avoid redoing work that other teammates have already done or switching to old branches. However, to get the full benefits of caching, you have to go beyond simply setting it up.