Mobile App Architecture & How To Start Building One

According to Grand View Research, the global mobile app market is expected to reach $626.39 billion by 2030, at a 14.3% CAGR. Indeed, more and more users of digital services want to have them at hand everywhere, and what else can provide this if not a smartphone? If you have also decided to launch your own mobile app, you should understand what components its architecture will consist of, as it is one of the main aspects determining its budget, compatibility, and scalability potential.

The Significance of a Robust Mobile App Architecture for a Business

Architecture is the basis of any modern mobile application, as it ensures its reliability, security, and scalability. Moreover, a properly constructed architecture eliminates the accumulation of technical debt, as well as ensures a quick response to user requests and the introduction of new functionality without compromising the stability of the project. In a business context, its correct choice allows you to quickly test hypotheses, conduct A/B testing, release updates without long downtimes, and integrate third-party services.

A Deeper Insight Into the Types of Mobile App Architectures

Now, let's consider the three main types of mobile app architecture and find out which one is best suited for your project.

Monolithic Architecture

A monolith is an app structure in which all application logic, interface, data handling, and communication are localized in a single module or container. This approach is always faster to implement and, in general, is optimal for solutions that do not imply further scaling. However, when the functionality expands, the monolith becomes difficult to support because changes require recompiling the entire project.

Microservices Architecture

Microservices allow you to distribute functionality across independent services, each of which is responsible for a specific task, whether it is authorization, payment, analytics, etc. This approach increases fault tolerance and scalability, and also enables different modules to be created by different teams. Its disadvantages are complicated communication, the need to build API gateways, and orchestration.

Layered Architecture

Layered architecture means dividing the application into Presentation, Business, and Data layers (we will tell you more about them below). This mobile architecture structures the code and is ideal for medium and large projects, as it makes code management more transparent, testing easier, and updates safer.

The Three Layers of Mobile App Development Architecture

In this section, we invite you to consider the three-tier architecture in more detail.

Presentation Layer

The presentation layer includes screens, UI elements, animations, navigation controls, etc. It is responsible for the user interface and user interaction with the mobile application. Sometimes this layer also includes the device requirements layer, i.e., adaptation to different screen sizes, orientations, system dialogs, and layouts.

Business Layer

The business layer (backend) includes the business logic of the mobile application, i.e., algorithms, state management, decision making, and synchronization. It processes UI requests, interacts with input data, executes API calls, and makes decisions.

Data Layer

The data layer is responsible for storing and collecting data. It takes care of accessing the REST API, caching responses, aggregating data, and serializing/deserializing it. When properly organized, this layer allows applications to work offline, synchronize with other services, and store the history of previous user interactions.

A Closer Look at Mobile Application Architectures for Different Platforms

It's time to talk about platform compatibility and how the choice of architecture affects it.

Android Mobile App Architecture

In native Android development, the most common architectural approach is Model-View-ViewModel (MVVM). According to it, the logic is handled by the layer that receives and processes data, and the device screen just displays the result. This approach makes the mobile app easy to maintain and update. The Model-View-Intent (MVI) approach is the other typical approach in Android development, in which screen management is even more centralized, and everything the user does goes through a one-way flow.

iOS Mobile App Architecture

In iOS development, it is also common to divide the application into parts: screen, logic, and data, and two architectural approaches perfectly correspond to this – Model-View-Controller (MVC) and the above-mentioned MVVM. MVC is easy to implement, but it is often criticized because as the functionality expands, the screen begins to take on too many tasks, which can hinder further app upgrades. That’s why developers often use MVVM, especially with the SwiftUI interface. According to it, the logic is placed in a separate layer, and the screen shows the result. As for large projects, they may require more complex schemes, such as VIPER or Clean Architecture.

Hybrid Mobile App Architecture

When there is a need to launch an app on both Android and iOS at once, but the budget or timelines do not allow you to develop each version separately, the development team can offer you a hybrid approach, for example, using React Native or Flutter. In this case, most of the code will be written in a universal form and will work on both platforms at once. As for architectural patterns, the most common ones are Business Logic Component (BLoC) or MVVM, which we mentioned above. However, regardless of the app architecture, such software may work more slowly, especially if the app logic affects the hardware of user devices.

Cross-Platform Mobile App Architecture

A cross-platform approach to development allows you to implement business logic once and tailor the screen design for Android and iOS separately. This is a bit more complicated than a hybrid, but ensures better flexibility and performance. Xamarin, Kotlin Multiplatform Mobile, or Ionic and Cordova are usually used as the main development tools – they provide the implementation of business logic through the browser inside the application.

‍If you are unsure which architecture will be the best choice for your mobile application, call us or write to us, and we will advise you on this matter.

Key Elements to Consider When Developing Mobile App Architecture

As practice shows, there is much more behind the effective architecture of a mobile application than the correct choice of design patterns and frameworks. It is also taking into account a number of factors, which we will discuss in more detail below.

Device Determination

A mobile application can be designed for smartphones, tablets, wearable devices, and embedded systems. Since all these devices have differences in screen sizes, graphics capabilities, and RAM, the architecture must take these differences into account to adapt the interface, caching, and resource consumption. It is also important to provide support for older devices if you create a product for a wide audience.

Bandwidth Status

User devices can be located both in a stable Wi-Fi zone and in conditions of poor mobile Internet or its complete lack. This requires designing an architecture with support for offline modes, as well as data resending mechanisms, caching, and fallbacks. It is also essential to take into account the volume of data transmitted to reduce the network load.

Right User Interface

The architecture should include approaches that enable separating business logic from presentation to simplify UI testing and eliminate critical bugs in it. In addition, developers should provide adaptivity, accessibility, dark themes, multi-language support, and real-time UI updates.

Navigation Approach

Navigation can be stack, tab, combined, or implemented through deep links. The chosen navigation approach should be independent of the UI state, otherwise, it will be difficult to manage the routes. The best option is to use centralized routing to avoid state conflicts and hard-to-fix bugs when switching between screens.

Real-Time Updates Vs. Push Notifications

There are apps that have to display information in real time, and there are those for which sending push notifications is enough. The architecture should consider this difference – real-time data requires a socket connection, Webhooks, or Firebase Realtime Database, while push notifications need the ability to process them at the business logic level.

Safety and Compliance

Processing user data requires compliance with local and international regulations, such as GDPR, HIPAA, PCI DSS, etc. The architecture should ensure data encryption during its storage and transmission, authentication via OAuth or JWT, and access rights control. In addition, it makes sense to implement a centralized event audit and logging system to minimize legal risks.

The Ability to Scale

The architecture should be built taking into account the growth of both the number of users and the data volume/the app’s functionality. This can be achieved through an initial choice in favor of a modular architecture, which means the inrtroduction of feature flags, building cache systems, as well as the implementation of CI/CD practices and ensuring a predisposition for containerization.

Integration with Third-Party Services

Almost all mobile applications do not work autonomously – usually, they require integration with payment gateways, maps, analytical systems, CRM, social networks, etc. Therefore, the architecture should include adaptation layers that can handle external events, repeat requests in case of errors, support SDKs of third-party platforms, and ensure fault-tolerance in case of unstable API operation.

Key Considerations to Choose the Right Type of Mobile Application Architecture

Architecture is not invariant – it is always selected for the specific business goals and app launch conditions. Below, we have described the main steps for making a final decision.

Understand Your Requirements

First, you should determine what the project result should be – an MVP, a full-fledged enterprise solution, an e-commerce app, etc. Also, the requirements include functionality, expected workloads, and business goals (monetization, retention, security, etc.). All these aspects will give you valuable insights that will later help you choose the right architectural option.

Analyze Development Resources

If your in-house team consists of only 2-3 developers, it will be difficult for them to implement the Uber-like architecture. You must also take into account the team's experience in specific architectural patterns, proficiency in mobile development tools, and understanding of CI/CD. Often, the architecture is simplified because of limited resources, and here you must analyze what is more important – to stretch the budget a little and hire third-party specialists for getting a scalable solution or to deal with what you already have.

Consider User Experience

Architecture directly affects how smoothly and quickly the app works. Specifically, if you need high UI responsiveness, minimal loading time, and local caching, the architecture should include state management, prefetch, offline-first, and other mechanisms. It is also worth considering multithreading and restrictions on access to the platform API.

Assess Performance Requirements

If the app needs to process a large data amount or, for example, uses animations, its architecture should include lazy loading, thread separation, as well as caching and buffering. Also, if it is based on AI or ML, you must initially choose an approach that separates the logic between the server and the client.

Build a Test App

It is better to implement a proof of concept once than to create a product that the audience will not accept. Usually, this means developing a prototype based on the selected architecture, which is deployed in a test environment. After evaluating its KPIs, you will be able to accurately identify bottlenecks and begin optimizing them.

Consider Future Scalability and Maintenance

The architecture you choose should allow your mobile app to scale. To do this, check how easy it is to add new modules, update dependencies, and implement A/B tests.

Research Frameworks and Tools

There are dozens of great solutions in the modern mobile development tools market, ranging from proprietary Google/Apple SDKs to third-party frameworks like Flutter, React Native, and Ionic. Understanding the pros and cons of each solution will help you avoid becoming dependent on technologies that aren’t right for you.

Assess Your Development Team's Readiness

The choice in favor of one or another technology stack should be made taking into account the expertise of your development team. Also, you have to evaluate how well your team understands layered architecture, its testing, CI/CD, and patterns. Based on this, you may have to add time for training/attracting external specialists to the initial deadlines.

Consider Budget and Time Constraints

Complex architectures require a lot of time to implement, including creating documentation, onboarding, unit tests, and setting up CI. If the deadline is tight, it is better to use ready-made architecture templates (in particular, they are provided by Google and Apple) – this will allow you to focus on the value for the end user.

Make an Informed Decision

This stage involves creating an architecture map with diagrams and layers, distributing tasks among the team members, and defining timelines. It is crucial to document all the steps in detail and include all the business requirements in the architecture from the very beginning, so that you do not have to start the project from scratch again in a year or two.

How Can Che IT Group Help with Your Mobile App Architecture

Che IT Group is an international company specializing in mobile app development. We know how to transform a raw idea into a profitable mobile application with a stable architecture. For this, we first conduct a requirements assessment, then implement a Proof-of-Concept with an emphasis on the mobile application security architecture, and then, based on feedback, build a fully functional application. Once it is launched, we will take on its further support and upgrading, introducing new functionality without accumulating technical debt. If you are interested in delegating a mobile development task to seasoned experts, feel free to contact us.