Coupang Android Architecture Part 2

Seongchul Park from Coupang reveals how they tackled a monolithic Android codebase with hundreds of thousands of lines of code. The solution? Strategic modularization that transformed both build times and code reusability.

This is part 2 of Coupang's architecture transformation series, focusing on how they broke down their monolithic Android app into distinct modules. After implementing MVP pattern for separation of concerns, they still faced long build times and needed better code reuse as the company expanded into new business sectors.

Key Takeaways

• Split monolith into app module, feature modules, and 13 core modules
• Maintained 80% unit test coverage across all new modules
• Core modules designed as libraries with configuration injection for reusability
• Feature modules minimized cross domain dependencies for independent operation
• Enabled support for Google's instant apps and app bundles

The article details their specific approach to handling third party library dependencies in core modules, a critical challenge most teams overlook during modularization.