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
• Xcode
• LibTooling
• LLVM
• ast-matchers

Code refactoring is an essential part of the job of software developers. As time goes on, technology evolves, product requirements change, and new features are built into a codebase. Find out how the iOS Collective at SoundCloud created a custom refactoring tool to transform more than 900 source files.

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

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

• 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.

• iOS
• Swift
• Testing

Memory leaks are a common problem when writing iOS applications, and while we all know we should be on the lookout for them, it’s often too easy to miss a vital weak reference. By leveraging integration testing, we can catch these issues and spend more time actually building features.

• Engineering
• iOS
• Architecture

In 2017, our team of six engineers wanted to try out a clean architectural pattern and decided to use VIPER. In the text below, I’ll cover how the team worked on this.

• 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.

• iOS
• Architecture

Growth in code bases come with exciting scalability challenges. As the size of our iOS codebase and team at SoundCloud grew, we faced challenges: long compile times and conflicts. Our productivity started to suffer as a result. We took inspiration from the work done in the backend (Building Products at SoundCloud) and applied it to mobile development. The main goal was to get back to a state where development is fun, fast, and would scale as the number of contributors grew. We modularized our iOS project by splitting it up into modules with well-defined responsibilities and public interfaces that interconnect them.

• iOS
• Mobile

When we rebuilt our iOS app, the player was the core focus. The interactive waveform was at the center of the design. It was important both that the player be fast and look good.

Initial implementation

We iterated on the waveform view until it was as responsive as possible. The initial implementation focused on replicating the design, which heavily used CoreGraphics. A single custom view calculates the current bar offset based on its time property. It then draws each of the waveform samples that are in the current visible section of the waveform. Each sample is either rendered as a filled rectangle for unplayed samples, or by adding clip paths to the context then drawing a linear CGGradient…

• iOS
• Mobile

Recently, SoundCloud launched the new iOS application which was a complete rewrite of the existing iOS application. The Mobile engineering team saw this as an opportunity to build a solid foundation for the future of SoundCloud on iOS and to experiment with new technologies and processes at the same time.

In the world of mobile, you deal with data, errors, threads and concurrency a lot. The common scenario starts with a user tapping on the screen. The application jumps off of the main UI thread…