Monolithic vs Microservices: Choosing the Right API Gateway for Your Architecture
API7.ai
March 7, 2025
Introduction
API gateways serve as the single entry point for client requests, handling authentication, load balancing, rate limiting, and traffic management. However, the architecture behind your application—monolithic vs microservices—directly influences how an API gateway should be selected and deployed.
In a monolithic architecture, API gateways typically act as simple reverse proxies, forwarding requests to a unified backend. In contrast, microservices architectures require more sophisticated routing, service discovery, and observability capabilities.
This article will explore how API gateway requirements differ between monolithic and microservices-based applications, discuss deployment strategies, and compare common API gateway solutions like NGINX, Spring Cloud Gateway, Kong, and Apache APISIX.
Understanding Monolithic and Microservices Architectures
What Is a Monolithic Architecture?
A monolithic architecture is a traditional software design approach where all application components (UI, business logic, and database access) are tightly integrated into a single codebase.
Characteristics of Monolithic Applications
- Single codebase and deployment unit
- Centralized database
- Synchronous communication between components
- Easier debugging and testing
- More challenging to scale horizontally
What Is a Microservices Architecture?
A microservices architecture breaks an application into smaller, independent services that communicate over a network. Each service has its own database and is deployed independently.
Characteristics of Microservices Applications
- Decoupled services with independent deployments
- Polyglot tech stack (different services can use different languages and databases)
- Service discovery and load balancing required
- More complex to manage, requiring observability and monitoring
API Gateway in Monolithic vs Microservices Architectures
Role of an API Gateway in a Monolithic Architecture
In a monolithic architecture, an API gateway acts primarily as a reverse proxy, handling:
✅ Request routing to a single backend service
✅ SSL termination
✅ Basic authentication and rate limiting
✅ Caching for performance optimization
Popular API Gateways for Monolithic Applications
- NGINX: High-performance reverse proxy with caching and load balancing capabilities
- Spring Cloud Gateway: Ideal for Java-based applications with tight Spring ecosystem integration
Since monolithic applications don’t have multiple services to manage, API gateways in this architecture are simpler and mainly focus on traffic management and security.
Role of an API Gateway in a Microservices Architecture
In a microservices environment, an API gateway serves a more complex role, handling:
✅ Dynamic routing between multiple backend services
✅ Load balancing and service discovery
✅ Authentication and authorization
✅ Circuit breaking and failover strategies
✅ Logging, monitoring, and observability
Popular API Gateways for Microservices Applications
- Kong: Extensible, Lua-based gateway with built-in service discovery
- Apache APISIX: High-performance API gateway with dynamic routing and real-time traffic management
Microservices-oriented API gateways need to be highly scalable, support dynamic configuration updates, and integrate well with Kubernetes and service mesh solutions.
Deployment Considerations for API Gateways
Monolithic API Gateway Deployment
- Typically deployed on-premise or as a standalone NGINX instance
- Configuration updates require a full reload of the gateway
- Limited need for advanced traffic management capabilities
Microservices API Gateway Deployment
- Containerized deployments (Docker, Kubernetes)
- Requires dynamic configuration management for service discovery
- Supports multi-layer security (JWT, OAuth, mTLS)
- Integrates with service meshes like Istio for east-west traffic management
| Feature | Monolithic API Gateway | Microservices API Gateway |
|---|---|---|
| Primary Function | Reverse proxy & security | Dynamic service routing & management |
| Scalability | Vertical scaling | Horizontal scaling with distributed deployment |
| Service Discovery | Not required | Required |
| Traffic Management | Basic load balancing | Advanced rate limiting & circuit breaking |
| Observability | Logs only | Metrics, tracing, and logs |
Best Practices for API Gateway Selection
When to Choose NGINX or Spring Cloud Gateway?
✅ Your architecture is monolithic
✅ You need basic request routing and security
✅ Your API traffic is low to moderate
When to Choose Kong or Apache APISIX?
✅ You have a microservices-based architecture
✅ You need dynamic traffic routing and real-time updates
✅ You require service discovery and plugin extensibility
Conclusion: Choosing the Right API Gateway for Your Architecture
The best API gateway for your application depends on your architecture.
- For monolithic applications, NGINX and Spring Cloud Gateway offer straightforward and reliable solutions.
- For microservices applications, Kong and Apache APISIX provide the necessary scalability, dynamic routing, and observability.
As microservices adoption grows, API gateway requirements will continue to evolve. Selecting the right tool for your architecture will ensure optimal performance, security, and scalability.
FAQ
1. Do I need an API gateway for a monolithic application?
While not always necessary, an API gateway can help with SSL termination, authentication, and basic request routing for monolithic applications.
2. What is the best API gateway for microservices?
Popular choices include Kong and Apache APISIX, which support dynamic routing, service discovery, and plugin extensibility.
3. Can I migrate from a monolithic API gateway to a microservices API gateway?
Yes. Many organizations start with NGINX or Spring Cloud Gateway and later transition to Kong or Apache APISIX as they adopt microservices.
Next Steps
Stay tuned for our upcoming column on the API Gateway Guide, where you'll find the latest updates and insights!
Eager to deepen your knowledge about API gateways? Follow our Linkedin for valuable insights delivered straight to your inbox!
If you have any questions or need further assistance, feel free to contact API7 Experts.