Backstage Blog

• iOS
• Swift
• Mobile
• Dependency Injection
• Dependency Inversion

As our codebase scales, the need for cleaner architecture becomes more apparent. The dependency inversion principle (DIP) is one tool that helps us build cleaner relationships among our software modules. In this post, DIP is presented using atomic modules and is later applied to frameworks.

• iOS
• Tuist
• Xcode
• XcodeGen
• Mobile
• Tooling

Learn how SoundCloud improved the productivity of its iOS engineers by using Tuist to generate Xcode projects.

• Android
• Dagger
• Performance
• Engineering
• Mobile
• Gradle

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.

• iOS
• Mobile
• Dark Mode
• Engineering
• Swift

Last week’s update to the SoundCloud iOS app includes support for Dark Mode. This took several months of work and collaboration between design and engineering teams across the company, so we wanted to share our approach to implementing Dark Mode and some of the obstacles we encountered along the way.

• Android
• Gradle
• Productivity
• Engineering
• Mobile

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.

• Android
• Gradle
• Productivity
• Engineering
• Mobile

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.

• Android
• Mobile
• Playback
• Media

Media and playback are at the core of SoundCloud’s experience. For that reason, we have established and grown an engineering team that is specialized in providing the best possible streaming experience to our users across multiple platforms.

To do this, we combine the industry’s best-fitting solutions with our own custom technologies, libraries, and tools. In this article, let’s dive into how we improved latency in our Android application by leveraging a new engine for our player’s audio sink.

• Android
• Mobile
• Release
• Testing
• Engineering

Once every two weeks, we prepare new versions of our mobile apps to be published to the app stores. Being confident about releasing software at that scale — with as many features and code contributions as we have and while targeting a wide range of devices like we do at SoundCloud — is no easy task. So, over the last few years, we have introduced many tools and practices in our release process to aid us.

In this blog post, I’ll cover some of the techniques we use to guarantee we’re always releasing quality Android applications at SoundCloud.

• Android
• Mobile
• Testing
• Firebase

Testing mobile applications is not always an easy feat. In addition to defining what to test and determining how to write those tests, actually running tests can also be problematic — in particular, UI test suites running on real mobile devices or emulators sometimes run for an extensive amount of time.

• iOS
• Testing
• Mobile

Apple introduced automated UI testing in Xcode 7. This was a great addition for developers because this native support promised, among other things, an improvement in the flakiness notoriously associated with automation tests. As many of us developers have experienced, tests can sometimes fail even when there has been no modification to the test or underlying feature code.