Architectural Principles and Layered Design
Understand the basics of layered design in mobile apps and learn the architectural principles.
Every mobile app begins with good intentions: a clean folder structure, a few screens, and code that feels easy to navigate. But as features multiply, teams grow, and deadlines tighten, that clarity begins to fade. Files expand. Logic spreads unpredictably. One change breaks three things. Suddenly, a once-simple app feels fragile, and no one is sure why. The reason the app isn’t working well is the lack of a proper structure. It has nothing to do with the quality of the code itself.
Mobile architecture is about defining clear boundaries, organizing responsibility, and creating a system that can absorb change without collapsing.
This chapter explores architecture patterns that help us tame complexity as mobile apps evolve. We’ll also explore the structural decisions that make codebases maintainable, adaptable, and resilient overtime. This chapter will cover the following:
At its core, mobile architecture exists to solve the recurring challenges mentioned below.
Platform fragmentation: iOS and Android follow distinct life cycle models and UI paradigms, requiring developers to account for platform-specific behavior and design conventions.
Frequent UI changes: User interface designs evolve rapidly, often leaving limited time for architectural refactoring or deep technical alignment.
Resource constraints: Mobile devices operate under strict limitations in memory, processing power, and battery life, necessitating efficient and optimized code.
Expanding codebase complexity: Continuous feature development, bug and quick fixes contribute to a growing and increasingly complex codebase overtime.
This brings us to the first architectural tool in our toolbox: architectural principles and layered design. It lays the groundwork for everything that follows: by separating responsibilities into distinct layers and enforcing design boundaries, we gain flexibility, clarity, and control.
With this context in mind, we now move into the principles that bring structure and discipline to architecture, starting with DRY, separation of concerns, and the SOLID rulebook.
Mobile architecture principles
A well-structured mobile system is the result of applying time-tested principles that bring clarity, reduce risk, and create a foundation for long-term success. These principles are not tied to any specific language or platform; they shape how developers think, organize, and evolve systems. This section presents the most influential architectural principles and how they bring order to mobile app development. Principles like DRY, separation of concerns, and ...