Optimising the future of Fabrik's apps

Modernising our native Android and iOS codebases by migrating to Kotlin and Swift.


As developers contributing to and maintaining the Android and iOS mobile apps that make up immedia’s Fabrik platform, there are a number of things we expect to happen during the lifespan of the mobile apps we deliver. Bugs will arise, new features will need to be ideated, and both Apple and Google will release major updates to their operating systems - to which our apps will be required to adapt.

At each of these junctures, we’ll need to respond quickly as, of high importance to ourselves and our clients, is the guarantee that as environmental challenges evolve, so do our mobile apps to meet these challenges. At a high level, there are 4 areas of coding support that Fabrik apps receive: 

  1. Corrective, better known as bug fixing. 

  2. Adaptive; adapting to the latest hardware and OS changes.

  3. Perfective; dealing with changes in user requirements.

  4. Preventative; code restructuring & optimisations aimed at reducing complexity and preventing future errors. 

The first three areas are fairly self-explanatory and commonly practiced as our team works hard to ship regular app updates for our Fabrik clients with the latest bug fixes and improvements, additional feature enhancements and finally, updates required to become compliant with the latest OSes.

However, as developers, we don’t readily reveal the ‘preventative’ part of what we do i.e. the behind-the-scenes code improvements, re-writes and optimisations that are implemented on an ongoing basis.


In this blog post, we offer some insight into what that looks like for Fabrik in particular, and how we’re working to ensure the longevity of our product through modernising our mobile app codebases.

When immedia’s development teams started to build Fabrik’s Android and iOS apps, the Objective-C coding language was initially used on iOS whereas Java was used on Android. Since then, alternatives from Apple (Swift for iOS) and Google (Kotlin for Android) have matured and become the gold standard for developing apps on their platforms. Now, any new app developer just starting out will default to using one of these newer languages rather than the 36-year old Objective-C or 20-year old Java. Swift is one of the fastest growing languages in history and, in 2019, Kotlin became Google’s preferred choice for Android development.

One of the key benefits of these languages is that they can be used in conjunction with their predecessors. On Fabrik, the code is currently a combination of the old and the new, and our endeavour now is to future-proof our source code as much as we can and systematically re-create as much code as possible into Swift and Kotlin.

However, for some features this interoperability does take some effort, so in order for us to keep delivering new features and app enhancements in the future, we’ll need to allocate time now to preventative maintenance with an expanded effort around code rewrites and optimisations. We will move quickly to ease out the historical languages in favour of the modern counterparts, so that our platform will continue to be operational today and for years to come. When we end this journey, our apps will be more efficient and less error-prone, which will make our investment of time and effort into these code migrations worthwhile. 


For the most part, Swift and Kotlin share the same ideologies and will deliver much of the same benefits on their respective platforms. 


Here are a few key points on why we’ve chosen to make these transitions: 


1. Speed

The new languages are fast; for example, a simple search algorithm has been benchmarked as being 2.6 times faster in Swift than Objective-C.