Modular iOS Architecture @ Just Eat

Talk given at Mobile London on 6/2/2020

https://www.meetup.com/Mobile-London/events/267907993/

Modular mobile architectures have been a hot topic over the past 2 years, counting a plethora of articles and conference talks. At Just Eat, we jumped on the modular iOS architecture train more than 3 years ago, before it was mainstream. I will walk you through the challenges we faced (technical and not), the historical company facts that brought us to having a modularized architecture, and give you some tips to start this journey in your apps too.

Transcript

1. Modular iOS Architecture @ Just Eat Alberto De Bortoli
2. A modular architecture is a software design technique that emphasises separating the functionality of a program into independent, interchangeable modules, such that each one contains everything necessary to execute only one aspect of the desired functionality. MODULAR ARCHITECTURE
3. AGENDA ▸ A bit of Just Eat history ▸ Challenges ▸ Learnings & advice
4. TIMELINE The Big Fork Single global platform work starts Modularization is completed Early 2014 June 2016 October 2019
5. “Integrate people first, technology later” Adam Gilmore Head of Engineering @ Just Eat
6. The iOS Team (a.k.a. the best team evah)
7. Your friends: the (product|delivery) managers
8. 2014 2016 2018 2019
10. CocoaPods-based
12. AVOID DEPENDENCY HELL ▸ The dependency issue arises around shared libraries on which other libraries have dependencies but where they depend on different and incompatible versions ▸ Sometimes duplication is better ▸ Low-level code shouldn’t change frequently, and our code changes frequently by definition
13. ▸ A flat dependency graph allows Xcode to parallelize the build process. source: https://patrickbalestra.com/ FLATTENED OUT DEPENDENCY GRAPH
14. ▸ Not an easy task! FLATTENED OUT DEPENDENCY GRAPH
15. THINK OPEN-SOURCE ▸ README ▸ Easy to integrate ▸ Tests ▸ Reasonably shaped code
16. THINK OPEN-SOURCE ▸ README ▸ Easy to integrate ▸ Tests ▸ Reasonably shaped code “I don't wanna use this library because it's not in MVVM.” - said nobody ever
17. DON'T BE FUSSY ABOUT (A SPECIFIC) ARCHITECTURE ▸ It's simply inevitable that different developers prefer different kinds of architecture ▸ Best to evangelise SOLID, Dependency Injection, Inversion of Control and all that jazz MVVM VIPER MVC MVP MVVM-C ELM
18. ▸ Only run the code you are working on ▸ Fast compilation times ▸ Jump straight to the desired features ▸ Get it for free with $ pod lib create DEMO APPS
19. REFERENCES ▸ Personal Twitter: @albertodebo ▸ Personal blog: albertodebortoli.com ▸ Just Eat blog: tech.just-eat.com ▸ Modular iOS Architecture @ Just Eat albertodebortoli.com/2019/12/19/modular-ios-architecture-at-just-eat ▸ iOS @ Scale(ish) by Bradley Smith @ Wayfair appdevcon.nl/session/ios-at-scaleish ▸ Improving Your Build Time in Xcode 10 patrickbalestra.com/blog/2018/08/27/improving-your-build-time-in-xcode-10.html