ConversionApp

🚀 Introduction

ConversionApp is a currency exchange application that allows users to convert between currencies using up-to-date exchange rates. It syncs rates from a remote API, applies commissions based on specific rules, and keeps track of user balances — all in real-time.

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🧰 Tech Stack & Libraries

• Jetpack Compose – Modern UI toolkit for native Android
• Koin – Lightweight dependency injection framework
• Ktor Client – HTTP client used for fetching exchange rates from a remote API
• Room – Local database for persisting currency rates
• DataStore – Store user preferences and app state persistently

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🧱 Architecture

ConversionApp follows a scalable and testable architecture:

• MVVM (Model-View-ViewModel) – For clear separation of concerns between UI and business logic
• Clean Architecture – Divides code into layers (UI, Domain, Data) to enforce boundaries and decoupling
• Layer Per Feature – Each feature (e.g., Exchange) has its own independent layers
• Modular Approach – Features and core layers are separated into modules for better reusability, testing, and build performance

🔍 Module Overview

• app is the main entry point and wires together the dependencies.
• feature:exchange handles the core exchange logic and business rules.
• feature:sync fetches the latest rates from the remote API and updates the database.
• feature:commission applies dynamic commission logic (e.g. first 5 free, 0.7% after).
• feature:balance manages the user's wallet-like balance.
• feature:settings stores preferences like the dark theme toggle.
• feature:transaction stores a history of completed exchanges.
• core:network, core:datastore, core:database, and core:designsystem are reusable base modules shared across features.

Each feature module depends only on what it needs and interacts with shared core modules through interfaces.

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