Building Microservices with .NET Core

As companies grow, their software systems also need to grow. More users start using the application, more data flows through the system, and customers request more features. Along with this growth, businesses also expect faster updates, fewer errors, and minimal downtime.

In traditional systems built using a monolithic architecture, everything is connected into one large application. This means even a small change in one part of the system may require redeploying the entire application. This often causes problems like system downtime, slow updates, a higher risk, and unhappy users.

This is exactly where microservices architecture becomes very useful.

Microservices allow applications to be broken into smaller, independent parts. This makes systems easier to manage, easier to scale, and faster to update.

At Sparkle Web, we help startups and enterprises upgrade their existing systems or build new platforms using .NET Core microservices, so they can grow smoothly, release features faster, and stay competitive.

In this guide, you will clearly understand:

What microservices really are
Why .NET Core is a great choice for microservices
How to build microservices step by step

Best practices to follow

Real-life use cases where microservices work best

What Are Microservices?

Microservices are a way of building software where the application is divided into small, independent services. Each service is responsible for one specific job or business function.

Instead of one large system doing everything, you have many small services working together.

Each microservice:

Works independently
Can be built and updated without touching other services
Has its own database

Can be deployed separately

Can be scaled separately when needed
Communicates with other services using APIs or messages

Example

Imagine an e-commerce application.

Instead of one big application, you can break it into:

User Service - handles login, signup, profiles
Product Service - manages products and categories
Order Service - handles orders and checkout

Payment Service - processes payments

If the payment system needs an update, only the Payment Service is changed. Other services continue working without interruption.

This separation makes systems more stable and easier to maintain.

Why Choose .NET Core for Microservices?

.NET Core (now simply called .NET) is one of the best platforms for building microservices. It is fast, reliable, and well-suited for modern cloud applications.

Key Benefits of .NET Core

Works on Windows, Linux, and macOS
Very fast and high-performing
Handles large traffic efficiently

Built-in support for dependency injection

Easy to build REST APIs and gRPC services
Works perfectly with Docker and Kubernetes
Strong security features
Trusted by enterprises worldwide

At Sparkle Web, we use ASP.NET Core because it allows us to build secure, scalable, and future-ready microservices that perform well even under heavy load.

Microservices Architecture Overview

A typical .NET Core microservices system includes several important parts working together.

Main Components

1. API Gateway

Acts as a single entry point for clients
Routes requests to the correct service
Handles authentication, rate limiting, and logging

Common tools: YARP, Ocelot

2. Microservices

Built using ASP.NET Core Web APIs
Each service has a specific responsibility

3. Databases

Each service has its own database
Examples: SQL Server, PostgreSQL, MongoDB

4. Communication

REST APIs for direct communication
gRPC for fast internal calls
Message queues for async communication

5. Authentication

JWT tokens
OAuth 2.0 for secure access

6. Monitoring and Logging

Tracks performance and errors
Helps fix issues quickly

Step-by-Step: Building Microservices with .NET Core

Step 1: Create a Microservice Project

Start by creating a new ASP.NET Core Web API project.

dotnet new webapi -n UserService
cd UserService
dotnet run

This creates a lightweight API that can run independently.

Step 2: Define a Controller

Controllers expose endpoints that other services or applications can call.

[ApiController]
[Route("api/users")]
public class UsersController: ControllerBase
{
    [HttpGet]
    public IActionResult GetUsers()
    {
        return Ok(new[]
        {
            new { Id = 1, Name = "John" },
            new { Id = 2, Name = "Sarah" }
        });
    }
}

Each microservice should keep controllers simple and focused on one task only.

Step 3: Use Independent Databases

Each microservice must own its data. Sharing databases creates tight coupling and problems later.

Example using Entity Framework Core:

services.AddDbContext<UserDbContext>(options =>
    options.UseSqlServer(Configuration.GetConnectionString("UserDb")));

This ensures the User Service can grow or change without affecting others.

Step 4: Service-to-Service Communication

REST Communication

Used when services need immediate responses.

var response = await httpClient.GetAsync("http://orderservice/api/orders");

Asynchronous Messaging (RabbitMQ)

Used when services should not wait for each other.

channel.BasicPublish(
    exchange: "",
    routingKey: "order.created",
    body: message
);

Async communication improves system stability and performance.

Step 5: Secure Microservices

Security is very important, especially for business and enterprise systems.

Using JWT authentication:

services.AddAuthentication("Bearer")
.AddJwtBearer(options =>
{
    options.Authority = "https://auth.sparkleweb.com";
    options.Audience = "microservices-api";
});

This ensures only authorised users and services can access APIs.

Step 6: Containerise with Docker

Docker allows services to run the same way in all environments.

Example Dockerfile:

FROM mcr.microsoft.com/dotnet/aspnet:8.0
WORKDIR /app
COPY . .
ENTRYPOINT ["dotnet", "UserService.dll"]

Docker makes deployment faster, easier, and more reliable.

Step 7: Orchestrate with Kubernetes (Optional)

For large systems, Kubernetes helps:

Automatically scale services
Restart failed containers
Manage deployments smoothly

Balance traffic

This is ideal for enterprise and high-traffic systems.

Best Practices for .NET Microservices

Keep each service small and focused
Use an API Gateway
Never share databases

Use centralized logging

Handle failures with retries
Automate builds and deployments
Monitor performance continuously
Design APIs carefully

Real-World Use Cases

Healthcare – Patient, appointment, and billing services
E-commerce – Orders, inventory, payments
Enterprise SaaS – Multi-tenant platforms

FinTech – Secure transactions and reporting

Startups – Easy scaling from MVP to enterprise

Conclusion

Industry data shows that microservices:

Increase deployment speed by 60%
Reduce downtime by up to 50%
Improve system reliability

Enable faster feature delivery

By using .NET Core microservices, businesses become more flexible, scalable, and ready for growth.

Sparkle Web Collaboration - Let’s Build It Right

At Sparkle Web, we specialise in:

.NET Core microservices
Cloud-native systems
API-first architecture

SaaS and enterprise platforms

Ready to upgrade or build your system? Contact us today. Let’s build scalable microservices together.

Contact Us : +91 90331 80795

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Building Microservices with .NET Core: A Step-by-Step Guide