5 Microservices Design Patterns You Must Know in 2025

Microservices have changed how we build software. Instead of creating one large application, you split it into smaller, independent pieces called services. Each service can do one job really well, making your system more flexible and scalable. But with flexibility comes complexity. This is where design patterns come in — they’re like blueprints to solve common problems.

I am a bestseller Udemy Instructor. Check out my top 10 Udemy courses with discounts: My Udemy Courses — Ramesh Fadatare.

Here are five important microservices design patterns you should know in 2025, explained in simple terms with examples.

Check out my bestseller Udemy course: [NEW] Building Microservices with Spring Boot & Spring Cloud. // best on Udemy

1. API Gateway Pattern

Imagine you’re shopping online. The website talks to many backend services — like one for user info, another for orders, and one for payments. If your app connects directly to all these services, it becomes messy and slow. That’s where an API Gateway helps.

Solution:

The API Gateway acts as a single entry point. Instead of connecting to multiple services, the client sends one request to the gateway, and it routes the request to the right services.

How It Works:

Client sends a request to the API Gateway.
Gateway forwards the request to the appropriate service(s).
Gateway can combine responses if needed and send them back to the client.

Example: Using Spring Cloud Gateway

@EnableGateway
@SpringBootApplication
public class ApiGatewayApplication {
    public static void main(String[] args) {
        SpringApplication.run(ApiGatewayApplication.class, args);
    }

    @Bean
    public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
        return builder.routes()
                .route("user-service", r -> r.path("/users/**")
                        .uri("lb://USER-SERVICE"))
                .route("order-service", r -> r.path("/orders/**")
                        .uri("lb://ORDER-SERVICE"))
                .build();
    }
}

This setup lets the client interact with multiple services through one simple gateway.

Best Practices:

Add caching to reduce repeated requests.
Use security features like OAuth2 or JWT.
Handle service failures with circuit breakers (explained below).

Complete API Gateway pattern tutorial: API Gateway Pattern in Microservices — A Complete Guide.

2. Saga Pattern

When multiple services are involved in a transaction, things get tricky. Imagine placing an order — one service deducts money, another updates inventory, and another creates the order. What if one step fails? The Saga Pattern ensures that all steps work together or everything rolls back cleanly.

Solution:

The Saga Pattern breaks a transaction into smaller steps. Each service handles its step and then triggers the next one. If something goes wrong, it can undo its step.

Types of Sagas:

Choreography: Each service knows what to do next.
Orchestration: A central controller decides what happens next.

Example: Choreography-Based Saga

User service reserves credit.
Order service creates the order.
Payment service completes the payment.

Code Snippet:

@EventListener
public void handleOrderCreatedEvent(OrderCreatedEvent event) {
    PaymentRequest paymentRequest = new PaymentRequest(event.getOrderId(), event.getAmount());
    paymentService.processPayment(paymentRequest);
}

Best Practices:

Ensure each step can handle retries without errors.
Use logs to track what happened in case of issues.
Test your sagas thoroughly to avoid data inconsistencies.

Complete Saga Pattern tutorial: Saga Pattern in Microservices: A Step-by-Step Guide.

3. Circuit Breaker Pattern

When a service fails or becomes slow, it can cause the entire system to break down. For example, if a payment service is down, all orders might fail. The Circuit Breaker Pattern helps by stopping calls to a failing service until it recovers.

Solution:

A circuit breaker acts like a switch:

Closed State: Requests go through as usual.
Open State: Requests are blocked to protect the system.
Half-Open State: Limited requests are sent to check if the service is working again.

Example: Using Resilience4j

@CircuitBreaker(name = "userService", fallbackMethod = "fallbackGetUser")
public User getUser(String userId) {
    return webClient.get()
            .uri("http://user-service/users/" + userId)
            .retrieve()
            .bodyToMono(User.class)
            .block();
}

public User fallbackGetUser(String userId, Throwable throwable) {
    return new User("default", "Guest");
}

If the user service is down, the fallback method returns a default user instead.

Best Practices:

Combine with retries for temporary failures.
Monitor metrics to tune thresholds.
Provide meaningful fallbacks so users aren’t left hanging.

4. Event Sourcing Pattern

Traditional systems only store the current state of data (e.g., a user’s account balance). But what if you need to know how that state changed over time? Event sourcing records every change as an event, giving you a full history.

Solution:

Instead of overwriting data, every change is saved as an event in an event store. You can replay these events to see how the data evolved.

Example: Order Service Event Sourcing

public class OrderCreatedEvent {
    private String orderId;
    private String userId;
    private List<String> items;
    // Getters and Setters
}

// Storing an event
EventStore.save(new OrderCreatedEvent(orderId, userId, items));

Best Practices:

Use tools like Apache Kafka to store events.
Take periodic snapshots to speed up rebuilding the current state.
Ensure events are immutable and well-documented.

5. Strangler Fig Pattern

Many companies have old, monolithic systems that are hard to maintain. Rewriting everything at once is risky and time-consuming. The Strangler Fig Pattern lets you modernize your system gradually.

Solution:

You replace parts of the old system with the microservices one piece at a time. Over time, the old system “shrinks” as microservices take over.

Example:

Identify a part of the monolith to replace (e.g., user management).
Create a microservice for the new functionality.
Use an API Gateway to route requests for /users to the new service.

Gateway Configuration:

routes:
  - id: user-service
    uri: lb://USER-SERVICE
    predicates:
      - Path=/users/**

Best Practices:

Start with smaller, less risky features.
Use metrics to monitor performance and issues during migration.
Document changes so teams can track the migration process.

Conclusion

Take the time to understand and implement these patterns in your projects. They’ll help you build systems that are not only efficient but also prepared for future challenges.

Which of these patterns have you used? Share your thoughts in the comments, and let’s help each other build better microservices!

Keywords: Microservices design patterns, API Gateway, Saga Pattern, Circuit Breaker, Event Sourcing, Strangler Fig, microservices best practices, scalable systems

Check out my bestseller Udemy course: [NEW] Building Microservices with Spring Boot & Spring Cloud. // best on Udemy

📢 Stay Connected & Keep Learning! 🚀

If you find my content valuable, please support with a clap 👏 and share it with others! 🚀

🔗 Explore my Udemy courses: Java Guides Udemy Courses
📖 Read more tutorials on my blog: Java Guides
🎥 Watch free Java video tutorials on YouTube: Java Guides YouTube //170K Subscribers

Java Guides

Search This Blog