architecture-patterns

Architecture Patterns

Overview

Architecture patterns provide proven solutions for structuring software systems. Choosing the right architecture is crucial for scalability, maintainability, and team productivity.

Patterns

Monolithic Architecture

Description: Single deployable unit containing all application functionality.

Key Features:

• Simple deployment and development
• Shared database and memory
• Straightforward debugging

Use Cases:

• MVPs and startups
• Small teams (< 10 developers)
• Simple domain logic

Best Practices:

src/
├── modules/          # Feature-based organization
│   ├── users/
│   ├── orders/
│   └── products/
├── shared/           # Cross-cutting concerns
└── infrastructure/   # External services

---

Microservices Architecture

Description: Distributed system of independently deployable services.

Key Features:

• Independent deployment and scaling
• Technology diversity per service
• Fault isolation

Use Cases:

• Large teams needing autonomy
• Complex domains with clear boundaries
• High scalability requirements

Key Components:

Component	Purpose	Tools
API Gateway	Entry point, routing	Kong, AWS API Gateway
Service Discovery	Service registration	Consul, Kubernetes DNS
Config Management	Centralized config	Spring Cloud Config, Consul
Circuit Breaker	Fault tolerance	Resilience4j, Hystrix

Best Practices:

1. Design around business capabilities
2. Decentralize data management
3. Design for failure
4. Automate deployment

---

Event-Driven Architecture

Description: Systems communicating through events.

Key Patterns:

Pattern	Description	Use Case
Event Sourcing	Store state as events	Audit trails, temporal queries
CQRS	Separate read/write models	High-read workloads
Saga	Distributed transactions	Cross-service workflows

Event Sourcing Example:

// Events are the source of truth
interface OrderEvent {
  id: string;
  type: 'OrderCreated' | 'ItemAdded' | 'OrderShipped';
  timestamp: Date;
  payload: unknown;
}

// Rebuild state from events
function rebuildOrder(events: OrderEvent[]): Order {
  return events.reduce((order, event) => {
    switch (event.type) {
      case 'OrderCreated': return { ...event.payload };
      case 'ItemAdded': return { ...order, items: [...order.items, event.payload] };
      case 'OrderShipped': return { ...order, status: 'shipped' };
    }
  }, {} as Order);
}