State Management in Mobile System Design

It’s the last date to fill out an application, and even in the last minutes, you’ve spent time carefully filling out a long form in an app. Just as you’re about to submit, you rotate your phone, and the screen reloads, wiping all your data. Or, you add several items at a flash sale to your shopping cart, switch to another app for a moment, and when you return, your cart is empty. These common frustrations are symptoms of the same core challenge: poor state management.

In our previous lesson, we explored how offline-first design adds even more complexity to this problem. Managing data that might be queued locally, actively syncing, or even in conflict requires a robust and well-defined state management strategy.

In this lesson, we’ll discuss the types of app states, explore the unique challenges mobile apps face, and learn about life cycle-aware tools and best practices that help prevent data loss and build user trust. Let’s start by understanding what a state is.

What is the state?

In mobile applications, state refers to the application’s current data or condition at a given point in time. It defines what the app knows and how it behaves based on that knowledge.

Effective state management is the key to creating smooth, reliable, and efficient user experiences. It ensures the app remembers user inputs and preferences across app switches, screen rotations, and even device restarts. Mobile devices have limited resources, intermittent connectivity, and complex life cycle events, requiring specialized approaches to maintain app consistency.

Types of states in mobile applications

To solve the problems we described, it is important to understand the different types of states that a mobile app needs to manage. As the diagram below illustrates, mobile app state can be grouped into four main categories, each differing in scope and lifetime:

Let’s explore each type of state in more detail to understand their roles and challenges.

• UI state: UI state governs what the user sees and interacts with on a particular screen or component. This includes elements like toggles, form inputs, scroll positions, or modal visibility. UI state is typically local and short-lived, and often resets when the user navigates away or the app restarts. Properly managing the UI state prevents frustrating data loss from events like screen rotations, and ensures responsive user interactions.

• Business logic state: The business logic state contains data that spans multiple screens or features and drives core app functionality, such as the user’s authentication status, shopping cart contents, or ongoing transactions. This state is generally global or shared across the app, and must remain consistent and often persistent across sessions.

• Persistent state: Persistent state refers to data stored locally on the device that survives beyond a single app session. This includes user preferences, cached API responses, or offline edits waiting to be synchronized. Persistence is typically achieved through platform-specific storage solutions such as SharedPreferences and SQLite on Android, or UserDefaults and Core Data on iOS.

• Server state: Server state encompasses data retrieved from remote APIs or back-end services that may change independently of the app. This includes data such as lists, user-generated content, or real-time updates fetched from a server. Rather than referring to any single piece of fetched data, the server state represents the authoritative source of truth maintained remotely. The app synchronizes with this source to stay up-to-date.

Understanding these different states sets the foundation for tackling the specific challenges mobile apps face in managing them effectively.

Challenges in state management

Managing the state of mobile devices presents unique challenges that arise from hardware limitations, platform differences, and complex application life cycles.