Architecture Constraints
Technical Constraints
Platform and Technology Stack
| Constraint | Description | Rationale | Negotiable |
|---|---|---|---|
| .NET Aspire | Cloud-native application framework | Simplified cloud-native development, built-in observability, service discovery | Low |
| Azure Container Apps | Primary deployment target | Managed container service with auto-scaling, serverless capabilities | Medium |
| Docker | Containerization platform | Consistent deployment across environments, isolation, portability | Low |
| PostgreSQL | Primary database system | ACID compliance, JSON support, open source, strong ecosystem | Medium |
| RabbitMQ | Message broker | Reliable message delivery, mature ecosystem, clustering support | Medium |
| Azure Services | Cloud platform dependency | Managed services, integration capabilities, cost optimization | Low |
Development Constraints
| Constraint | Description | Impact | Negotiable |
|---|---|---|---|
| Domain-Driven Design | Mandatory architectural approach | Influences service boundaries and model design | No |
| Vertical Slice Architecture | Required code organization | Affects project structure and feature implementation | Low |
| Event-Driven Architecture | Required communication pattern | Impacts service interaction and data consistency | Low |
| CQRS Pattern | Command Query Responsibility Segregation | Separates read and write operations, increases complexity | Medium |
| OpenAPI/AsyncAPI | API documentation standards | All APIs must be properly documented | Low |
Performance Constraints
| Constraint | Description | Impact | Rationale |
|---|---|---|---|
| Response Time | API responses under 500ms (95th percentile) | Requires efficient algorithms and caching | User experience requirements |
| Scalability | Support 10,000 concurrent users | Influences architecture patterns and resource planning | Business growth expectations |
| Memory Usage | Efficient memory management | Affects data structures and caching strategies | Cost optimization |
| Database Performance | Query execution under 100ms (90th percentile) | Requires proper indexing and query optimization | System responsiveness |
Organizational Constraints
Solo Development Context
| Constraint | Description | Impact | Mitigation |
|---|---|---|---|
| Single Developer | One person handles all roles | Limited bandwidth, knowledge silos | Comprehensive documentation, automated testing |
| Time Constraints | Part-time development schedule | Slower feature delivery | Prioritized feature development, MVP approach |
| Budget Limitations | Cost-conscious technology choices | Preference for free/open source solutions | Azure free tier, open source tools |
| Knowledge Transfer | Ensure project continuity | Extensive documentation required | Living documentation, decision records |
Development Process
| Constraint | Description | Rationale | Negotiable |
|---|---|---|---|
| Open Source Development | Public repository with MIT license | Community contributions, transparency | No |
| GitHub Actions | CI/CD pipeline platform | Free for public repos, integrated with GitHub | Low |
| Code Quality Gates | SonarCloud integration required | Maintain code quality standards | Low |
| Testing Requirements | Minimum 80% code coverage | Ensure reliability and maintainability | Medium |
Documentation Requirements
| Constraint | Description | Standard | Negotiable |
|---|---|---|---|
| Architecture Documentation | arc42 template compliance | Structured architectural documentation | Low |
| API Documentation | OpenAPI for REST, AsyncAPI for events | Industry standard API documentation | No |
| Event Catalog | Centralized event documentation | Event-driven architecture transparency | Low |
| ADRs | Architecture Decision Records | Decision rationale preservation | Low |
Political and Legal Constraints
Compliance Requirements
| Constraint | Description | Impact | Compliance Level |
|---|---|---|---|
| GDPR | EU data protection regulation | Data handling, user consent, privacy by design | Mandatory |
| PCI DSS | Payment card industry standards | Payment processing security requirements | Mandatory |
| Accessibility | WCAG 2.1 AA compliance | UI/UX design constraints | High |
| Open Source Licensing | MIT license compatibility | Third-party dependency restrictions | Mandatory |
External Dependencies
| Constraint | Description | Risk Level | Mitigation Strategy |
|---|---|---|---|
| Third-party APIs | External service dependencies | Medium | Fallback mechanisms, circuit breakers |
| Cloud Provider Lock-in | Azure-specific services | Medium | Abstraction layers, standard interfaces |
| Open Source Libraries | Dependency on community projects | Low | Active maintenance verification, alternatives |
Conventions and Standards
Coding Standards
| Convention | Description | Enforcement | Tool |
|---|---|---|---|
| EditorConfig | Consistent code formatting | Automatic | IDE integration |
| C# Coding Conventions | Microsoft C# standards | Code review | StyleCop, SonarCloud |
| Nullable Reference Types | Enabled for null safety | Compiler | C# compiler |
| Pattern Matching | Preferred over traditional conditionals | Code review | Developer discipline |
| File Scoped Namespaces | Modern namespace declaration | Code review | EditorConfig |
Architecture Patterns
| Pattern | Application | Justification | Mandatory |
|---|---|---|---|
| Microservices | Service decomposition | Scalability, independent deployment | Yes |
| Event Sourcing | Domain events storage | Audit trail, temporal queries | Yes |
| Outbox Pattern | Reliable event publishing | Message delivery consistency | Yes |
| Inbox Pattern | Idempotent message processing | Duplicate prevention | Yes |
| Saga Pattern | Distributed transactions | Long-running process management | Yes |
| CQRS | Read/write separation | Performance optimization | No |
Naming Conventions
| Element | Convention | Example | Rationale |
|---|---|---|---|
| Services | Domain.Service format | Catalog.Service | Clear service identification |
| Events | PastTense.DomainEvent | OrderPlaced.Event | Event naming clarity |
| Commands | Imperative.Command | CreateOrder.Command | Action intention |
| Queries | Question.Query | GetBookById.Query | Query purpose |
| APIs | RESTful resource naming | /api/v1/books | Industry standard |
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
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