Module Design

Purpose

Break down system architecture into discrete, implementable modules with well-defined boundaries, interfaces, and responsibilities.

When to Use

• After architecture design approved
• Before development starts
• When planning sprint work
• For complex feature decomposition

Prerequisites

• Architecture documentation
• Component diagrams
• Data models defined

Process

Step 1: Identify Module Boundaries

Boundary criteria:
- Single responsibility
- High cohesion within
- Low coupling between
- Clear ownership

Step 2: Define Module Interfaces

Interface definition:
- Public API (exposed functions)
- Events emitted/consumed
- Data contracts
- Dependencies

Step 3: Create Module Specification

Specification includes:
- Purpose and scope
- Public interface
- Internal structure
- Dependencies
- Testing approach

Step 4: Validate Design

Validation:
- Meets requirements
- Fits architecture
- Testable
- Maintainable

Step 5: Document Design Decisions

Documentation:
- Design rationale
- Alternatives considered
- Trade-offs made

Inputs

Input	Type	Required	Description
architecture_doc	Markdown	Yes	System architecture
requirements	Markdown	Yes	Feature requirements

Outputs

Output	Type	Description
module_specs/	Markdown	Module specifications
interface_docs/	Markdown	API definitions

StudyAbroad-Specific Considerations

• University module (search, details, sync)
• Application module (CRUD, workflow, validation)
• Document module (upload, storage, retrieval)
• User module (profile, preferences, GDPR)
• Auth module (OAuth, JWT, sessions)

Integration Points

• Architecture Agent: Receives architecture
• Developer Agent: Implements modules
• Test Manager: Test planning

Examples

Module: Application

Purpose: Manage study abroad applications through their lifecycle

Public Interface:
  - createApplication(userId, programId): Application
  - updateApplication(id, data): Application
  - submitApplication(id): Application
  - getApplication(id): Application
  - getUserApplications(userId, filters): Application[]
  - cancelApplication(id): void

Events:
  - application.created
  - application.submitted
  - application.statusChanged

Dependencies:
  - User module (user data)
  - University module (program validation)
  - Document module (attachments)
  - Notification module (emails)

Internal Structure:
  src/application/
  ├── application.module.ts
  ├── application.controller.ts
  ├── application.service.ts
  ├── application.repository.ts
  ├── dto/
  │   ├── create-application.dto.ts
  │   ├── update-application.dto.ts
  │   └── application-response.dto.ts
  ├── entities/
  │   └── application.entity.ts
  ├── events/
  │   └── application.events.ts
  └── __tests__/
      ├── application.service.spec.ts
      └── application.controller.spec.ts

Validation

• All requirements mapped to modules
• Interfaces clearly defined
• Dependencies documented
• No circular dependencies
• Testability verified