2. Architecture Constraints

2.1 Technical Constraints

Platform and Technology Stack

Constraint	Description	Rationale
.NET 9	Latest .NET framework	Access to newest features and performance improvements
.NET Aspire	Cloud-native application framework	Simplified cloud-native development and deployment
Azure Container Apps	Primary deployment target	Managed container service with auto-scaling
Docker/Podman	Containerization platform	Consistent deployment across environments

Development Constraints

Constraint	Description	Impact
Domain-Driven Design	Mandatory architectural approach	Influences service boundaries and model design
Vertical Slice Architecture	Required code organization	Affects project structure and feature implementation
Event-Driven Architecture	Required communication pattern	Impacts service interaction and data consistency
CQRS Pattern	Command Query Responsibility Segregation	Separates read and write operations
OpenAPI/AsyncAPI	API documentation standards	All APIs must be properly documented

2.2 Organizational Constraints

Development Process

• Open Source Development: Public repository with community contributions
• MIT License: Permissive licensing for maximum flexibility
• GitHub Actions: CI/CD pipeline for automated testing and deployment
• Code Quality: SonarCloud integration for code quality metrics
• Testing Strategy: Comprehensive testing including unit, integration, and load testing

Documentation Requirements

• Architecture Documentation: arc42 template compliance
• API Documentation: OpenAPI for REST APIs, AsyncAPI for events
• Event Catalog: Centralized event-driven architecture documentation
• Deployment Guides: Comprehensive deployment instructions

2.3 Conventions and Standards

Coding Standards

• EditorConfig: Consistent code formatting across the project
• C# Coding Conventions: Microsoft C# coding standards
• Nullable Reference Types: Enabled for better null safety
• Pattern Matching: Preferred over traditional conditional logic

Architecture Patterns

Pattern	Application	Justification
Microservices	Service decomposition	Scalability and independent deployment
Event Sourcing	Domain events storage	Audit trail and temporal queries
Outbox Pattern	Reliable event publishing	Ensures message delivery consistency
Inbox Pattern	Idempotent message processing	Prevents duplicate message processing
Saga Pattern	Distributed transactions	Manages long-running business processes

2.4 Infrastructure Constraints

Deployment Environment

• Azure Cloud: Primary cloud provider
• Container-based: All services deployed as containers
• Managed Services: Preference for managed Azure services
• Infrastructure as Code: Automated infrastructure provisioning

Security Requirements

• Authentication: Keycloak for identity management
• Authorization: Role-based access control (RBAC)
• HTTPS Only: All communication encrypted in transit
• Secret Management: Azure Key Vault for sensitive configuration
• Security Scanning: Automated vulnerability scanning

2.5 External Dependencies

Third-Party Services

Service	Purpose	Constraint Impact
Keycloak	Identity and access management	Authentication architecture dependency
SendGrid	Email delivery service	Email functionality limitation
Azure Services	Cloud infrastructure	Platform-specific implementation
AI Models	Nomic Embed Text, Gemma 3	GPU requirements for local development

Hardware Requirements

• GPU Support: Required for AI components in local development
• Container Runtime: Docker or Podman for local development
• Memory: Minimum 8GB RAM for full local development setup
• Storage: SSD recommended for optimal performance