PickMe Apr 5, 2025

Mastering SOLID Principles in Android with Jetpack Compose & Kotlin

Article Summary

Chamod Lakmal from PickMe Engineering breaks down SOLID principles with real Jetpack Compose code examples. No theory fluff—just practical refactoring patterns that actually work in production Android apps.

This guide walks through all five SOLID principles (Single Responsibility, Open-Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion) with before-and-after Kotlin code samples. Each principle includes concrete Compose examples showing how to separate UI logic, extend functionality without modification, and use dependency injection properly.

Key Takeaways

Critical Insight

Applying SOLID principles in Jetpack Compose creates modular, testable Android apps by separating concerns and depending on abstractions rather than concrete implementations.

The article reveals a common LSP violation that crashes apps and shows exactly how to fix it with proper inheritance.

About This Article

Problem

Android developers building Jetpack Compose applications often struggle when UI logic, business logic, and data handling all live in the same composable functions. This tight coupling makes code harder to maintain and scale.

Solution

Chamod Lakmal shows how to apply SOLID principles through practical Kotlin refactoring. The approach involves splitting composables into separate state-management and UI-rendering layers, using sealed classes for polymorphic behavior, and adding Hilt dependency injection to handle repository abstractions.

Impact

When developers follow these five design principles, they can build Android codebases that are modular and testable. New features can be added without changing existing code, which means fewer bugs and less technical debt in production.