Tweetzy: An Android Tweet Viewer

Tweetzy is a modern Android application meticulously engineered with Jetpack Compose for a declarative UI, utilizing MVVM architecture, Dagger-Hilt for Dependency Injection, and Kotlin Coroutines/Flows for a reactive data pipeline, all driven by a Retrofit service for API access that performs server-side data filtering via a custom X-JSON-Path header.

✨ Key Features & Technology Stack

This project was built to showcase a complete implementation of the latest Android development practices, emphasizing clean architecture and reactive programming.

💻 Tech Stack

Category	Technology	Purpose
UI	Jetpack Compose	Declarative, state-driven UI construction.
Architecture	MVVM	Clean separation of concerns (Model, View, ViewModel).
Dependency Injection	Dagger-Hilt	Robust, scalable injection of services and ViewModels.
Networking	Retrofit & OkHttp	REST API client for fetching tweet data.
State Management	Kotlin Flows / StateFlow	Managing reactive, thread-safe data flow from Repository to UI.
Concurrency	Kotlin Coroutines	Structured concurrency for non-blocking network operations.
Navigation	Compose Navigation	Type-safe handling of screen routing and passing arguments (e.g., category ID).

Data & API

The application uses Retrofit to fetch data from an external JSON service: JSONBin (https://jsonbin.io/).

It demonstrates advanced API interaction by utilizing the special X-JSON-Path header for server-side data filtering. This ensures that only the data required for the selected category is retrieved, optimizing data transfer.

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Key Points

Developing the Tweetzy application provided practical experience and key insights into several complex areas of modern Android development:

• Reactive Data Synchronization: Mastering the use of MutableStateFlow within the Repository and correctly observing it with collectAsState() in the Composable UI. This was critical in resolving the initial blank screen issue.
• Hilt and Coroutine Scopes: Understanding how Hilt injects dependencies into ViewModels and managing the lifecycles of network calls using the viewModelScope to prevent memory leaks.
• Compose Navigation with Arguments: Correctly defining the navigation graph (NavHost), passing parameters between screens (e.g., passing the selected category string), and retrieving them safely within the target ViewModel via SavedStateHandle.
• Advanced API Filtering: Implementing and debugging the use of custom HTTP headers (X-JSON-Path) with Retrofit to perform complex data filtering directly on the backend, optimizing the data payload sent to the client.

This project represents a solid foundation in building maintainable, high-performance Android applications using the latest Jetpack libraries.