A modular monolith is the optimal approach to prototype microservice boundaries without diving into distributed system complexities. It allows you to decouple logic, establish async contracts, and define clear service boundaries before transitioning to microservices.
Key Benefits:
- Decoupled logic and data access
- Clear async communication contracts
- Internal interfaces for better separation
- Easier extraction into microservices when needed
🔗 Reference: Modular Monolith Communication Patterns
You Should Know: Practical Steps & Code Examples
1. Decoupling Logic in a Modular Monolith
Use dependency injection (DI) and clean architecture to separate concerns:
// Define interfaces for module communication
public interface IOrderService
{
Task<Order> CreateOrderAsync(OrderRequest request);
}
// Implement in a separate module
public class OrderService : IOrderService
{
public async Task<Order> CreateOrderAsync(OrderRequest request)
{
// Business logic here
}
}
2. Async Communication with Message Brokers
Use RabbitMQ or Azure Service Bus for async module communication:
Install RabbitMQ in Linux sudo apt-get install rabbitmq-server sudo systemctl start rabbitmq-server
// Publish a message
var factory = new ConnectionFactory() { HostName = "localhost" };
using var connection = factory.CreateConnection();
using var channel = connection.CreateModel();
channel.QueueDeclare(queue: "orders", durable: false, exclusive: false, autoDelete: false);
var message = JsonSerializer.Serialize(order);
var body = Encoding.UTF8.GetBytes(message);
channel.BasicPublish(exchange: "", routingKey: "orders", body: body);
3. Internal Interfaces for Isolation
Define internal contracts to prevent direct dependencies:
// In the "Orders" module
internal interface IOrderRepository
{
Task SaveOrderAsync(Order order);
}
// In the "Payments" module
public class PaymentService
{
private readonly IOrderRepository _orderRepo;
public PaymentService(IOrderRepository orderRepo)
{
_orderRepo = orderRepo;
}
}
4. Extracting a Module into a Microservice
Once ready, extract a module using Docker and Kubernetes:
Dockerize a .NET module docker build -t orderservice -f Dockerfile . docker run -d -p 8080:80 orderservice Deploy to Kubernetes kubectl apply -f orderservice-deployment.yaml
What Undercode Say
Modular monoliths bridge the gap between monoliths and microservices, reducing early-stage complexity. Key takeaways:
✔ Linux Command: Use `systemctl` to manage RabbitMQ (sudo systemctl status rabbitmq-server)
✔ Windows Command: Deploy modules using `docker-compose up -d`
✔ Best Practice: Start with sync calls before moving to async messaging
✔ Future-Proofing: Design modules like future microservices
🚀 Expected Output: A scalable, maintainable system that can evolve into microservices with minimal refactoring.
Prediction
Modular monoliths will dominate early-stage SaaS architectures, reducing premature microservice adoption failures by 30% in the next two years.
References:
Reported By: Milan Jovanovic – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
