Importance of Adopting Modularity in Mobile Application Development

Abu Bäkr
5 min readJul 4, 2024


In the fast-paced world of mobile application development, choosing the right architectural approach is crucial for creating apps that are scalable, maintainable, and adaptable to changing user needs. One such approach gaining traction is Modular Architecture, which offers significant advantages over traditional monolithic structures.

What is the issue with current approach?

Traditionally, apps have been built using monolithic architecture, where all components are tightly integrated into a single unit. Making updates or adding new features to it often requires modifying the entire codebase. This can lead to:

  • Complexity: With everything interconnected, understanding the entire codebase becomes daunting. It’s like trying to navigate through a maze without a map.
  • Rigidity: Changes in one part of the app can inadvertently affect others, leading to unexpected bugs or errors. It’s akin to fixing one thing only to break something else unintentionally.
  • Scalability Issues: As apps grow in size and complexity, scaling becomes challenging. It’s like trying to expand a single-story house into a skyscraper — it’s not feasible without extensive reconstruction.

Where does Modularity come in?

Modularity revolutionizes app development by breaking down the entire application into smaller, independent parts known as modules. Think of these modules as specialized Lego pieces, each designed to perform a specific function within the app. Just like Lego pieces can be individually tested and assembled into various configurations, modules in a modular app architecture are developed and tested independently. This approach offers developers significant flexibility — they can add, remove, or update modules without disrupting the entire application. Moreover, this modular approach enhances maintainability by isolating potential issues within specific modules, making debugging and updates more manageable and efficient. Thus, modular architecture not only simplifies the development process but also ensures that apps are scalable, robust, and easier to evolve over time.

Why Modularity?

Modularity addresses several critical aspects that are challenging in monolithic designs:

  1. Separation of Concerns: Modular Architecture promotes the separation of concerns by dividing the application into modules, each handling a distinct aspect of functionality. For example, in a social media app, modules can be dedicated to user profiles, messaging, notifications, and content management. This isolation ensures that each module focuses solely on its designated functionality, making the codebase easier to understand, modify, and maintain.
  2. Enhanced Reusability: By encapsulating functionality into modules with well-defined interfaces, Modular Architecture encourages reusability of code components. Modules developed for one application can be reused in others, reducing development time and effort. For instance, a module responsible for social media login can be reused in a different app developed by the same team, maintaining consistency and reliability across projects.
  3. Improved Development Workflow: Breaking down an application into modules facilitates a more streamlined development workflow. Development teams can work on individual modules concurrently, allowing for parallel development and reducing dependencies between teams. This approach not only accelerates the overall development process but also enhances collaboration among team members, as each module can be developed, tested, and integrated independently.
  4. Simplified Testing and Debugging: Modular Architecture simplifies the testing and debugging process by isolating modules. Each module can be tested independently, which improves the accuracy and efficiency of testing efforts. Debugging becomes more straightforward as issues are confined within specific modules, making it easier to pinpoint and resolve problems without affecting the entire application.
  5. Scalability: Scalability is inherently supported in Modular Architecture as applications grow. Instead of scaling the entire monolithic application, developers can scale specific modules based on demand. For example, in an e-commerce app, if the checkout process experiences increased traffic, the checkout module can be optimized independently, ensuring smooth performance without affecting other modules like product browsing or customer reviews.
  6. Faster Build Times: Modular Architecture contributes to faster build times by minimising the scope of recompilation. When changes are made to a specific module, only that module needs to be recompiled and integrated into the larger application. This reduces build times significantly compared to monolithic architectures, where changes often necessitate rebuilding the entire application, even if only a small portion has been modified.

Does Modularity have any drawbacks too?

Yes. While Modular Architecture offers many benefits, there are however some challenges to consider:

  1. Learning Curve: Switching from traditional methods to Modular Architecture requires understanding new concepts and practices. It may take time for developers to get used to this approach.
  2. Managing Complexity: As your app grows, keeping track of how modules interact and ensuring they communicate effectively can become complex. Careful planning and design are essential.
  3. Initial Setup: Setting up modules and defining their boundaries requires upfront planning and investment. It’s like designing the layout of rooms in a house before construction begins.

Any tips on how it can be improved?

Yes here are some tips to successfully implement Modular Architecture in your iOS app development so that you overweigh the benefits.

  1. Good Planning: Think about what each part of your app will do and what each part must be responsible for, and then divide your app into those modules. Often times, drawing and laying out your whole app for this purpose proves to be useful.
  2. Independent Modules: Design modules so they can work on their own without relying too much on other parts of the app. This makes testing and troubleshooting easier.
  3. Code Reusability: Build modules that can be used in different parts of your app or even in future projects. It’s like using the same blueprint for different houses.
  4. Keep Modules Small: Aim for smaller, focused modules that do one thing well. This makes them easier to understand, maintain, and update.
  5. Iterate and Improve: Modular Architecture is a continuous process. Regularly review and refine your modules based on user feedback and changing requirements.


By breaking down complex systems into modular components, developers not only simplify development processes but also lay a robust foundation for future app enhancements. While challenges like the learning curve and increased complexity persist, strategic planning and adherence to best practices can mitigate these issues, ensuring that the benefits of Modular Architecture far outweigh its challenges.

In the next part, we will see how we can implement Modularity in an iOS application using SPM. After using it, our app will look like below where every module will be in its own package;

We will use DI pattern using Factory for injecting dependencies, Coordinators for navigation and MVVM along with Clean as supporting architecture.

Feel free to reach out if you have any questions.
Good day! 🙌