Architecture with Claude: Backend and Frontend
Architecture design is where Claude truly excels. Thanks to its transparent reasoning, Claude can help you explore trade-offs, compare architectural patterns, and make informed decisions that will influence the entire project lifecycle.
In this article, we'll see how to use Claude to design backend architectures with Spring Boot and frontend with Angular, applying Solution Architecture best practices.
What You'll Learn
- Use Claude for architectural decisions with trade-offs
- Design Spring Boot backends with Clean/Hexagonal Architecture
- Structure Angular frontends with scalable patterns
- Define API contracts between frontend and backend
- Handle versioning and error handling
Claude's Role in Architecture
Claude can take on the role of Solution Architect and guide you through complex decisions. The key is to provide sufficient context and explicitly ask for trade-off analysis.
System Prompt: Solution Architect
You are a Senior Solution Architect with 15+ years of experience
in enterprise software development.
EXPERTISE:
- Microservices architecture (Spring Boot, Kubernetes)
- Frontend architecture (Angular, React, Vue)
- Event-driven systems (Kafka, RabbitMQ)
- Cloud platforms (AWS, Azure, GCP)
- DDD, Clean Architecture, Hexagonal
COMMUNICATION STYLE:
- Always explain trade-offs for every recommendation
- Use diagrams (ASCII or Mermaid) when helpful
- Cite industry standards (12-factor app, SOLID, etc.)
- Challenge assumptions when they seem problematic
CONSTRAINTS:
- Prioritize maintainability over cleverness
- Consider team size and skill level
- Focus on practical, implementable solutions
- Always address security implicationsBackend Architecture: Spring Boot
Recommended Architectural Patterns
Backend Pattern Comparison
| Pattern | Complexity | When to Use | Trade-off |
|---|---|---|---|
| Layered (MVC) | Low | Simple CRUD, MVP | Less flexible, high coupling |
| Clean Architecture | Medium | Complex business logic | More code, learning curve |
| Hexagonal | Medium-High | Multiple integrations, testability | Initial overhead, ports/adapters |
| CQRS | High | Asymmetric read/write, scalability | Infrastructure complexity |
Example: Hexagonal Architecture with Spring Boot
Hexagonal Spring Boot Structure
order-service/
├── src/main/java/com/company/orders/
│ ├── domain/ # Core Business Logic
│ │ ├── model/
│ │ │ ├── Order.java # Aggregate Root
│ │ │ ├── OrderItem.java
│ │ │ └── OrderStatus.java
│ │ └── service/
│ │ └── OrderDomainService.java
│ │
│ ├── application/ # Use Cases / Ports
│ │ ├── port/
│ │ │ ├── in/ # Inbound Ports
│ │ │ │ ├── CreateOrderUseCase.java
│ │ │ │ └── GetOrderQuery.java
│ │ │ └── out/ # Outbound Ports
│ │ │ ├── OrderRepository.java
│ │ │ └── PaymentGateway.java
│ │ └── service/
│ │ └── OrderApplicationService.java
│ │
│ ├── adapter/ # Infrastructure
│ │ ├── in/web/
│ │ │ └── OrderController.java
│ │ └── out/persistence/
│ │ └── OrderJpaRepository.java
│ │
│ └── config/
│ └── BeanConfiguration.javaFrontend Architecture: Angular
Recommended Patterns for Angular
Angular Frontend Patterns
| Pattern | Complexity | When to Use |
|---|---|---|
| Feature-based | Low | Small/medium projects, single team |
| Smart/Dumb Components | Medium | Reusability, testability |
| Signals + Services | Medium | Modern state management, Angular 17+ |
| NgRx | High | Enterprise, complex state, advanced debugging |
Service with Signals
order.service.ts - State Management with Signals
@Injectable({{ '{' }} providedIn: 'root' {{ '}' }})
export class OrderService {{ '{' }}
private http = inject(HttpClient);
// State
private ordersSignal = signal<Order[]>([]);
private loadingSignal = signal(false);
private errorSignal = signal<string | null>(null);
// Public readonly signals
readonly orders = this.ordersSignal.asReadonly();
readonly loading = this.loadingSignal.asReadonly();
readonly error = this.errorSignal.asReadonly();
// Computed signals
readonly pendingOrders = computed(() =>
this.ordersSignal().filter(o => o.status === 'PENDING')
);
loadOrders(): void {{ '{' }}
this.loadingSignal.set(true);
this.errorSignal.set(null);
this.http.get<Order[]>('/api/orders').pipe(
catchError(err => {{ '{' }}
this.errorSignal.set('Error loading orders');
return of([]);
{{ '}' }}),
finalize(() => this.loadingSignal.set(false))
).subscribe(orders => this.ordersSignal.set(orders));
{{ '}' }}
{{ '}' }}API Contract: Frontend-Backend
API Contract - Orders
## Orders API v1
### Create Order
POST /api/v1/orders
Content-Type: application/json
Request:
{{ '{' }}
"customerId": "cust_123",
"items": [
{{ '{' }} "productId": "prod_456", "quantity": 2 {{ '}' }}
],
"shippingAddress": {{ '{' }}
"street": "123 Main St",
"city": "New York",
"zipCode": "10001"
{{ '}' }}
{{ '}' }}
Response 201 Created:
{{ '{' }}
"id": "ord_789",
"status": "PENDING_PAYMENT",
"total": 99.99,
"createdAt": "2025-02-01T10:00:00Z"
{{ '}' }}
Response 400 Bad Request:
{{ '{' }}
"type": "validation_error",
"title": "Validation Failed",
"status": 400,
"errors": [
{{ '{' }} "field": "items", "message": "At least one item required" {{ '}' }}
]
{{ '}' }}Conclusion and Next Steps
In this article, we've seen how to use Claude to design solid architectures for Spring Boot backends and Angular frontends.
In the next article, we'll dive into code structure: folder organization, naming conventions, separation of concerns, and configuration management.
Key Takeaways
- Trade-off first: Always ask Claude to analyze pros/cons
- Hexagonal for integrations: Isolate business logic from technical details
- Signals for Angular 17+: Simple and reactive state management
- API contract: Define it before implementing
- Document decisions: Use ADR to track choices