Explained: Android Architecture Patterns [& Their Differences]

Ever wondered how some Android apps seamlessly handle complex logic while others struggle to maintain stability?

The secret lies in the Android architectural patterns they use.

Android architecture patterns serve as the backbone of app development, shaping how code is structured and components interact.

But with many options available, how do you choose the right one for your project?

This article will explore five popular patterns’ differences, strengths, and weaknesses, perfect for a curious novice or experienced developer wanting to learn more.

And if you’re considering partnering with an Android development agency, understanding these patterns can help you make informed decisions about your project’s architecture!

What is Android Architecture?

Android architecture means the structural design and organization of the Android operating system, outlining how its various components interact to make an application function.

The Android architecture consists of several layers, each serving specific purposes and functionalities:

• Linux kernel. It provides low-level hardware abstraction, memory management, device drivers, and security features, acting as the foundation of the Android OS being built.
• Hardware Abstraction Layer (HAL). It abstracts the hardware-specific implementations, allowing the upper layers of the Android stack to access hardware components (such as camera, display, and sensors).
• Native libraries. Android includes a set of native libraries written in C/C++ that provide core system functionalities, such as graphics rendering (OpenGL ES), multimedia playback (Media framework), and database management (SQLite). These libraries enable efficient and optimized performance for various system-level tasks.
• Android Runtime (ART). ART is the managed runtime environment responsible for executing Android applications.
• Java API framework. The Java API Framework provides the higher-level application framework and APIs. It includes various core libraries and components for activities, services, content providers, broadcast receivers, and user interface (UI) elements.
• System services. Android includes a set of system services that run in the background and provide essential functionalities to applications, such as activity management and network connectivity. These services ensure the smooth operation of the system and facilitate interaction between system components.
• Application framework. It provides developers with high-level building blocks and tools for creating Android applications. It includes components such as Activity Manager, Window Manager, and Content Providers, enabling developers to build robust and feature-rich applications.

Why Does Your App Need Good Architecture?

Here are several reasons why your app needs good architecture:

• Scalability. A well-designed architecture allows your app to scale effectively, accommodating increases in user base, data volume, and feature complexity without compromising performance.
• Performance. Implementing architectural patterns, such as caching, lazy loading, and asynchronous processing, can improve app responsiveness, reduce latency, and enhance the overall user experience.
• Security. Good architecture promotes security best practices by applying proper data handling, authentication, authorization, and encryption mechanisms, helping you mitigate common security threats and protecting user privacy.
• Testability. A well-structured architecture makes testing easier. It helps you check if your app works well, is reliable, and runs smoothly. You can also test each part separately by designing components with clear boundaries and minimal dependencies.

Popular Android Architecture Patterns

Popular Android architecture patterns are frameworks and guidelines that developers use to structure their Android applications effectively.

These patterns help address common challenges in app development, such as managing complexity, separating concerns, and promoting scalability.

Here are some of the most popular Android architecture patterns:

MVC

Model-View-Controller (MVC) is one of the oldest and most straightforward architecture patterns.

It divides the app into three main components:

• Model. It represents the data and business logic of the application, summarizing the application’s state and behavior, including data retrieval, manipulation, and storage. The Model notifies the Controller of any changes in the data, ensuring that the View is updated accordingly.
• View. The View represents the application’s UI of the application, including screens, widgets, and layouts that users interact with, typically using XML layout files and UI components. The View sees changes in the Model and updates its presentation accordingly.
• Controller. The Controller serves as an intermediary between the Model and the View. It receives user input events from the View, processes them, and updates the Model or View accordingly. In Android, Controllers are often implemented as Activity or Fragment classes that handle user interactions and manage the application’s behavior.

MVC separates the application’s logic (Model and Controller) from its presentation (View), making it easier to understand and maintain.

Its modular structure allows developers to reuse components across different parts of the application, improving code organization and reducing duplication.

While MVC provides a basic separation of concerns, it can lead to tight coupling between components, making it challenging to modify or replace one component without affecting the other.

MVP

Model-View-Presenter (MVP) builds on MVC by separating the presentation logic from the UI layer.

Here’s a detailed explanation of each component:

• Model. The Model is independent of the UI layer and does not directly interact with the View. Instead, it notifies the Presenter of any changes in the data, allowing the Presenter to update the View accordingly.
• View. Unlike traditional MVC, the View in MVP is passive and does not contain any business logic. Instead, it assigns user interactions to the Presenter and observes changes in the data model to update its presentation accordingly.
• Presenter. The Presenter in MVP is responsible for handling all presentation logic, including formatting data for display, validating user input, and responding to user interactions.

This Android architecture pattern improves testability and has a clear separation of concerns, making the codebase easier to maintain.

Separating the presentation logic from the UI components allows developers to write unit tests for the Presenter without needing to interact with the Android framework or UI elements directly, so they can easily adapt to design changes.

However, MVP requires writing additional boilerplate code to manage the communication between the View and the Presenter, which can make the development time longer and more complex.

MVVM

Model-View-ViewModel (MVVM) has gained popularity since the early days of the Windows Presentation Foundation (WPF).

This Android architecture pattern helps keep your code organized and easy to maintain, making it a favorite among developers.

Here’s a detailed description of each element:

• Model. The Model is independent of the UI layer and does not directly interact with the View or ViewModel. Instead, it provides data to the ViewModel and notifies observers of any changes in the data.
• View. Similar to MVP, The View in MVVM is only for handling UI-related events, it doesn’t handle any business logic. It delegates data binding and event handling to the ViewModel and detects changes in the ViewModel to update the presentation accordingly.
• ViewModel. The ViewModel gets data from the Model and prepares it for display in the View. It also shares observable properties and commands that the View can connect to. This lets the View update automatically whenever the data changes.

Compared to MVC and MVP, MVVM promotes better testability, reusability, and maintainability.

MVVM uses data binding to automatically synchronize the View with the ViewModel, reducing boilerplate code and making UI updates more efficient and consistent.

However, as MVVM introduces a new architectural pattern, this architecture pattern may require developers to learn new concepts and best practices, especially if they’re more familiar with other patterns such as MVC or MVP.

It may also be overkill for simple applications because it adds complexity and overhead compared to simpler architectural patterns like MVC.

MVI

Model-View-Intent (MVI) is an architectural pattern inspired by reactive programming principles.

It emphasizes unidirectional data flow and immutable state, making it easier to reason about the application’s behavior.

Let’s discuss MVI elements in more detail:

• Model. The Model represents the application’s current state. It summarizes data and business logic and is immutable. In the MVI pattern, changes to the Model are triggered by Intents and sent through the system using unidirectional data flow.
• View. The View is responsible for rendering the UI and displaying information to the user. In the MVI pattern, the View is a passive element that receives state updates from the Model and renders them accordingly. It also captures user interactions and converts them into Intents to be processed by the system.
• Intent. This represents user actions in the Android app. They’re sent from the View to the Model to trigger state changes. Intents are immutable and contain the necessary information to describe the user’s action.

MVI uses a unidirectional data flow, making it easier to understand and manage the application state.

The use of an immutable state in MVI also helps prevent bugs related to mutable state and simplifies debugging and testing.

The main drawback is that it can be more complex to set up and learn than other architectural patterns.

As it’s more complex, MVI may increase your app’s verbosity.

Clean Architecture

Clean Architecture, introduced by Robert C. Martin, supports a layered architecture with clear boundaries between components.

It consists of multiple layers with its own responsibility and level of abstraction.

• Entities. This layer contains the business logic and core domain models of the application. Entities represent the key concepts and rules of the domain and are independent of any specific framework.
• Use Cases (Interactors). These manage the application’s business rules and coordinate interactions between different parts. They outline the steps and tasks that can be done in the system, acting as go-betweens connecting outside requests with the core functions.
• Interfaces (Controllers, Presenters). This layer defines the system boundaries and interacts with external agents, such as users, databases, or network services. It translates external requests into internal operations and vice versa, handling input validation, data formatting, and errors.
• Frameworks and Drivers (Frameworks, Gateways). It contains the external frameworks, libraries, and infrastructure components that the application depends on.

The clear boundary makes the development process more flexible and scalable because changes to one layer won’t affect the other layers, making it well-suited for large and complex projects.

Some popular apps that use this pattern are Telegram, Spotify, and Instagram.

Still, setting up Clean Architecture from scratch may need more upfront planning and development effort compared to simpler architectural approaches.

Yet, the long-term benefits in terms of maintainability and scalability often justify this initial investment.

Which is The Right Architecture for My App?

Choosing the right architecture for your app depends on various factors.

Here’s a list of considerations to make better decisions when picking your Android architecture pattern.

Size and Complexity

For smaller projects with straightforward requirements, a simpler architecture like Model-View-Controller (MVC) or Model-View-Presenter (MVP) may suffice because they help speed up your Android development timeline.

However, for larger and more complex applications, architectures like Clean Architecture or Model-View-ViewModel (MVVM) provide better scalability and maintainability.

Also, make sure you choose an architecture that aligns with your project requirements and provides the necessary features to meet the project goals.

Team Expertise

Consider the expertise of your development team.

If your team is familiar with a particular architecture and has experience working with it effectively, it may be beneficial to stick with that architecture.

On the other hand, if your team is open to learning new approaches and they have the time to do so, you may explore more advanced architectures.

Future Scalability

Think about the future scalability of your application.

Will your app need to accommodate future enhancements, features, or changes in technology?

Choose an architecture that allows for easy scalability and adaptation to future requirements without significant refactoring.

In this regard, Clean Architecture will be a better option as it allows independent development and testing of components.