System Architecture Documentation

Table of Contents

  1. Architecture Overview
  2. System Design Principles
  3. Component Architecture
  4. Data Architecture
  5. Security Architecture
  6. Integration Architecture
  7. Deployment Architecture
  8. Performance Architecture

Architecture Overview

MS-Project follows a modern microservice architecture pattern with clean architecture principles at its core. The system is designed for high scalability, maintainability, and reliability.

High-Level Architecture Diagram

┌─────────────────────────────────────────────────────────────┐
│                         Clients                             │
│  (Web App, Mobile App, Third-party Systems)                │
└─────────────────┬───────────────────────────────────────────┘
                  │
                  ▼
┌─────────────────────────────────────────────────────────────┐
│                    API Gateway Layer                        │
│              (Load Balancer + Rate Limiting)                │
└─────────────────┬───────────────────────────────────────────┘
                  │
                  ▼
┌─────────────────────────────────────────────────────────────┐
│                 Authentication Service                       │
│                  (ForwardAuth + JWT)                        │
└─────────────────┬───────────────────────────────────────────┘
                  │
                  ▼
┌─────────────────────────────────────────────────────────────┐
│                    MS-Project Core                          │
│  ┌──────────────┬─────────────┬──────────────────────┐    │
│  │   Handlers   │  Services   │     Repositories      │    │
│  │   (Fiber)    │   (Logic)   │       (GORM)         │    │
│  └──────────────┴─────────────┴──────────────────────┘    │
└─────────────────┬───────────────────────────────────────────┘
                  │
                  ▼
┌─────────────────────────────────────────────────────────────┐
│                     Data Layer                              │
│  ┌─────────────┬──────────────┬────────────────────┐      │
│  │ PostgreSQL  │    Redis      │   S3 Storage       │      │
│  │  (Primary)  │   (Cache)     │   (Files)          │      │
│  └─────────────┴──────────────┴────────────────────┘      │
└─────────────────────────────────────────────────────────────┘

System Design Principles

1. Clean Architecture

The system follows Uncle Bob's Clean Architecture principles:

┌────────────────────────────────────┐
│         Presentation Layer         │
│        (HTTP Handlers)             │
├────────────────────────────────────┤
│         Business Layer             │
│     (Services & Use Cases)         │
├────────────────────────────────────┤
│         Domain Layer               │
│      (Models & Entities)           │
├────────────────────────────────────┤
│      Infrastructure Layer          │
│    (Database, External APIs)       │
└────────────────────────────────────┘

2. Domain-Driven Design (DDD)

  • Bounded Contexts: Projects, Tasks, Products, Users
  • Aggregates: Project (root), Task (root), Product
  • Value Objects: Status, Priority, ProjectProgress
  • Domain Events: TaskCreated, CommentAdded, StatusChanged

3. SOLID Principles

  • Single Responsibility: Each service handles one domain
  • Open/Closed: Extensible through interfaces
  • Liskov Substitution: Interfaces over concrete types
  • Interface Segregation: Small, focused interfaces
  • Dependency Inversion: Depend on abstractions

4. Event-Driven Architecture

EventEmitter
    ├── TaskCreatedEvent
    ├── TaskUpdatedEvent
    ├── CommentAddedEvent
    ├── StatusChangedEvent
    └── ProjectApprovedEvent

Component Architecture

Core Components

1. API Layer (/internal/handlers)

handlers/
├── project_handler.go    # Project endpoints
├── task_handler.go       # Task endpoints
└── base_handler.go       # Common functionality

Responsibilities:

  • HTTP request/response handling
  • Input validation
  • Error formatting
  • Response serialization

2. Service Layer (/internal/services)

services/
├── project_service.go    # Project business logic
├── task_service.go       # Task business logic
└── comment_service.go    # Comment operations

Responsibilities:

  • Business logic implementation
  • Transaction management
  • Event emission
  • Cross-service coordination

3. Repository Layer (Models)

models/
├── base.go              # Base model with ULID
├── project.go           # Project entity
├── task.go             # Task entity
├── product.go          # Product entity
├── product_attribute.go # EAV attributes
└── task_comment.go     # Comment entity

Responsibilities:

  • Data persistence
  • Query optimization
  • Relationship management
  • Data validation

4. Middleware Layer (/internal/middleware)

middleware/
├── auth.go             # JWT validation
├── permissions.go      # Permission checks
├── rate_limit.go      # Rate limiting
└── logger.go          # Request logging

Component Interaction Flow

Client Request
    ↓
API Gateway
    ↓
Authentication Middleware
    ↓
Permission Middleware
    ↓
Handler (Controller)
    ↓
Service (Business Logic)
    ↓
Repository (Data Access)
    ↓
Database

Data Architecture

Database Design Philosophy

1. Entity-Attribute-Value (EAV) Pattern

Used for the flexible product system:

products (Core Entity)
    ├── id
    ├── name
    ├── type
    └── ...

product_attributes (Attributes)
    ├── product_id
    ├── attribute_key
    ├── attribute_value
    └── attribute_type

2. Soft Deletes

All entities support soft deletion:

type BaseModel struct {
    ID        string       `gorm:"primaryKey"`
    CreatedAt time.Time
    UpdatedAt time.Time
    DeletedAt sql.NullTime `gorm:"index"`
}

3. Audit Trail

History tables track all changes:

project_histories
task_histories
comment_histories

Data Flow Architecture

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│   Create    │────▶│   Validate  │────▶│    Save     │
└─────────────┘     └─────────────┘     └─────────────┘
                            │                    │
                            ▼                    ▼
                    ┌─────────────┐     ┌─────────────┐
                    │  Emit Event │     │  History    │
                    └─────────────┘     └─────────────┘

Caching Strategy

┌────────────┐
│   Request  │
└─────┬──────┘
      ▼
┌────────────┐  Miss   ┌────────────┐
│   Cache    │────────▶│  Database  │
└─────┬──────┘         └─────┬──────┘
      │ Hit                  │
      ▼                      ▼
┌────────────┐         ┌────────────┐
│   Return   │◀────────│   Update   │
│            │         │   Cache    │
└────────────┘         └────────────┘

Security Architecture

Authentication Flow

┌──────────┐     ┌───────────┐     ┌──────────┐
│  Client  │────▶│    API    │────▶│   Auth   │
└──────────┘     └───────────┘     │  Service │
     ▲                              └─────┬────┘
     │                                    │
     │           ┌───────────┐           │
     └───────────│    JWT    │◀──────────┘
                 └───────────┘

Authorization Model

Permissions Structure:
├── Resource-based
│   ├── projects:view-all
│   ├── projects:create
│   ├── projects:update
│   └── projects:delete
└── Task-based
    ├── tasks:view-assigned
    ├── tasks:create
    ├── tasks:update
    └── tasks:change-status

Security Layers

  1. Network Security

    • TLS/SSL encryption
    • API Gateway firewall
    • Rate limiting

  2. Application Security

    • JWT token validation
    • Permission-based access
    • Input sanitization
    • SQL injection prevention

  3. Data Security

    • Encryption at rest
    • Encrypted passwords
    • Sensitive data masking
    • Audit logging

Integration Architecture

External Service Integration

MS-Project
    ├── Auth Service (ms-auth)
    ├── Notification Service (ms-notifications)
    ├── File Service (ms-files)
    └── Search Service (ms-search)

Integration Patterns

1. Synchronous Communication

Service A ──HTTP/REST──▶ Service B
         ◀──Response────

2. Asynchronous Communication

Service A ──Event──▶ Message Queue ──▶ Service B

3. File Storage Integration

Application ──▶ S3 API ──▶ Object Storage
            ◀── Pre-signed URL

Deployment Architecture

Container Architecture

ms-project:
  ├── Dockerfile
  ├── docker-compose.yml
  └── kubernetes/
      ├── deployment.yaml
      ├── service.yaml
      ├── configmap.yaml
      └── secrets.yaml

Kubernetes Deployment

┌─────────────────────────────────────┐
│         Kubernetes Cluster          │
├─────────────────────────────────────┤
│  ┌───────────┐  ┌───────────┐     │
│  │    Pod    │  │    Pod    │     │
│  │ MS-Project│  │ MS-Project│     │
│  └───────────┘  └───────────┘     │
│         │              │           │
│  ┌─────────────────────────┐      │
│  │      Service (LB)       │      │
│  └─────────────────────────┘      │
│         │                          │
│  ┌───────────┐  ┌───────────┐    │
│  │ PostgreSQL│  │   Redis   │    │
│  │    Pod    │  │    Pod    │    │
│  └───────────┘  └───────────┘    │
└─────────────────────────────────────┘

Scaling Strategy

Horizontal Pod Autoscaling (HPA)
├── Target CPU: 70%
├── Min Replicas: 2
├── Max Replicas: 10
└── Scale Down Delay: 5 minutes

Performance Architecture

Performance Optimization Strategies

1. Database Optimization

-- Indexes
CREATE INDEX idx_projects_status ON projects(status);
CREATE INDEX idx_tasks_project_id ON tasks(projectId);
CREATE INDEX idx_products_project_id ON products(projectId);

-- Connection Pooling
MaxIdleConns: 10
MaxOpenConns: 100
ConnMaxLifetime: 1 hour

2. Query Optimization

// Preload associations efficiently
db.Preload("Tasks").Preload("Products").Find(&project)

// Use selective fields
db.Select("id", "name", "status").Find(&projects)

// Batch operations
db.CreateInBatches(tasks, 100)

3. Caching Strategy

Cache Layers:
├── Application Cache (In-memory)
├── Redis Cache (Distributed)
└── CDN Cache (Static assets)

Cache TTL:
├── User data: 5 minutes
├── Project list: 1 minute
├── Static data: 1 hour
└── Configuration: 24 hours

4. API Response Optimization

// Pagination
GET /api/v1/projects?page=1&limit=50

// Field filtering
GET /api/v1/tasks?fields=id,name,status

// Compression
Content-Encoding: gzip

Performance Monitoring

Metrics Collection:
├── API Response Times
├── Database Query Duration
├── Cache Hit Ratio
├── Error Rates
├── Throughput (req/sec)
└── Resource Utilization

Resilience Patterns

1. Circuit Breaker

CircuitBreaker {
    FailureThreshold: 5
    SuccessThreshold: 2
    Timeout: 30s
    HalfOpenRequests: 3
}

2. Retry Logic

Retry {
    MaxAttempts: 3
    BackoffStrategy: Exponential
    InitialDelay: 100ms
    MaxDelay: 5s
}

3. Bulkhead Pattern

Bulkhead {
    MaxConcurrent: 100
    MaxWaitingRequests: 50
    Timeout: 10s
}

4. Health Checks

HealthCheck {
    Database: /health/db
    Redis: /health/redis
    Dependencies: /health/deps
    Overall: /health
}

Technology Stack Details

Core Technologies

  • Language: Go 1.24 (Performance, concurrency)
  • Web Framework: Fiber v2 (Express-like, fast)
  • ORM: GORM (Feature-rich, migrations)
  • Database: PostgreSQL 15+ (ACID, JSON support)
  • Cache: Redis 7+ (Performance, pub/sub)
  • ID Generation: ULID (Sortable, unique)

Development Tools

  • Testing: Testify + Testcontainers
  • API Docs: Swagger/OpenAPI 3.0
  • Linting: golangci-lint
  • Formatting: gofmt + goimports
  • Security: gosec

Infrastructure

  • Container: Docker 24+
  • Orchestration: Kubernetes 1.28+
  • Service Mesh: Istio (optional)
  • Monitoring: Prometheus + Grafana
  • Logging: ELK Stack
  • Tracing: Jaeger

Conclusion

The MS-Project architecture is designed to be:

  • Scalable: Handles growth through horizontal scaling
  • Maintainable: Clean architecture ensures code clarity
  • Reliable: Multiple resilience patterns prevent failures
  • Performant: Optimized at every layer
  • Secure: Defense in depth approach
  • Flexible: Adapts to changing requirements

This architecture provides a solid foundation for enterprise-grade project management while maintaining the flexibility to evolve with business needs.