0.5. Architecture: System Design & Tech Stack

[billjsan]

User Story: "As the Architect, I want to create a high-level system architecture diagram so that I have a clear blueprint of how the mobile client, backend API, and database will interact."
Primary Use Case: Creating a diagram showing the Mobile App (Kotlin), the REST API (Spring Boot), and the Database (PostgreSQL/MySQL). This diagram should illustrate the main data flows and service boundaries.
Effort Estimate: S
Product/Market Risk: Lack of a clear architectural plan can lead to tightly-coupled components that are difficult to maintain, scale, and test independently.

[billjsan]

Sub-task 5.1: Formally document the selected technology stack: Mobile App (Kotlin), REST API (Spring Boot), and Database (PostgreSQL/MySQL).
Sub-task 5.2: Create a high-level system architecture diagram that visually represents the three core components (Mobile Client, Backend API, Database).
Sub-task 5.3: On the diagram, draw and label the main data flow lines for critical actions (e.g., User Authentication, List Synchronization).
Sub-task 5.4: Clearly define the boundaries and responsibilities of each component in the diagram.
Sub-task 5.5: Schedule a technical review of the architecture diagram with the development lead/architect.