Mobile Architecture and Modularity Questions

High level architectural principles and practical patterns for building maintainable, scalable mobile applications and codebases. Topics include modular design and decomposition into feature modules, shared libraries, and core infrastructure components; defining clear module boundaries and application programming interfaces between modules; dependency management and versioning; strategies to avoid circular dependencies; patterns for inter module communication such as event driven messaging, callbacks, and dependency injection; separation of concerns between presentation, business logic, and data layers; build and continuous integration considerations for modular projects; packaging and deployment strategies; approaches to evolve architecture as teams and codebases grow, including code ownership, incremental refactoring, and migration plans; and ensuring modularity supports testability, observability, and performance at scale.