tl;dr: The programming language used to develop new features by our iOS app engineering team is changing from Objective C to Swift at some point in the near future.

When making a native app, the language you have to implement the app in is chosen by the third party responsible for the platform. For iOS apps, Apple chose Objective C to be the language the app is written in. Objective C is a... very strange language. It has a lot of quirks that slow down development.

To solve the above problem, you can now write apps in a new language called Swift. Notably, Swift has features that make it less error prone and more concise than Objective C, which should increase our velocity of feature development. Swift is also much more readable and in-line with other languages, which lowers the barrier of entry (which is currently very high with Objective C).

Importantly, Objective C and Swift can live alongside each other. So, when we "switch to Swift" we do not need to rewrite all of our existing code from Objective C to Swift. Instead, we can just start developing new features using Swift, and slowly rewrite the old code from Objective C into Swift as time allows.

On the downsides, Swift is only supported on iOS 7 and above. iOS 6 only represents around 5% of our user base, and we can pin iOS 6 users to the last version of the app we released before we used Swift. We need to decide what the last set of features we're want in that build are before we switch.

Here are our next steps:

• Evaluate more concretely whether Swift actually fits our needs or not. [Engineering]
• Decide last set of features for our iOS 6 build. [Product/Design]

Thanks,

Dan

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Dan Garry

Associate Product Manager, Mobile Apps

Wikimedia Foundation