What are microservices?

Microservices are a software development approach in which applications are broken down into small, independent (micro)services that work together to provide a larger overall system.

How do they work though?

Each microservice is responsible for a specific capability and communicate with other microservices through API’s or other lightweight messaging protocols.

For example, let’s say you have a user authentication service, a product catalog service, and a payment processing service. Each of these services would be responsible for a specific function within the application and would communicate with each other through APIs or other lightweight messaging protocols

How do I use them in my app


  • Identify the different business functions of your application.
  • Determine which functions can be broken down into smaller, independent services.
  • Each microservice should be responsible for a single business function.


  • Develop each microservice independently.
  • Each microservice should communicate with other microservices through APIs or other lightweight messaging protocols.
  • Microservices can be developed using different programming languages, frameworks, and tools.


  • Test each microservice independently.
  • Test each microservice in combination with other microservices.
  • Use automated testing tools to ensure that each microservice is functioning as expected.


  • Deploy each microservice independently.
  • Use containerization tools like Docker to package each microservice.
  • Use orchestration tools like Kubernetes to manage and scale your microservices.

Containerization Tools

Containerization tools like Docker allow you to encapsulate each microservice within an isolated container, which includes all the required dependencies and runtime environment. By packaging microservices into individual containers, you can ensure consistent behavior across different stages of development, deployment, and production. Moreover, containerization helps in simplifying the management and scaling of complex systems, as each service can be updated, replaced, or scaled independently.

Orchestration Tools

Orchestration tools like Kubernetes play a crucial role in managing and scaling microservices. Kubernetes automates the deployment, scaling, and management of containerized applications, taking the burden of manual deployment and resource allocation off your shoulders. It ensures your services are always running in the most efficient manner possible, adjusting to traffic patterns and system needs dynamically.


  • Developers can use different programming languages, frameworks, and tools for each microservice as needed, which can help improve development speed and agility.
  • Microservices are designed to be highly modular and scalable, so that developers can easily add or remove services as needed to meet changing business requirements.
  • Microservices can help improve fault tolerance and resilience, as failures in one microservice are less likely to affect the entire system
  • Microservices can help reduce the complexity of large applications, as each service can be developed, tested, and deployed independently.


  • Microservices can require additional effort to ensure that services are secure and protected from malicious attacks, which can increase development and testing time.
  • Microservices can require additional overhead, such as the need for containerization and orchestration tools, which can increase development and deployment costs.
  • Microservices can require additional effort to ensure that services are communicating effectively with each other, which can increase development and testing time.


This will go through incorporating Docker and Kubernetes into a microservices architecture with the example of an e-commerce application.

Our e-commerce application consists of several microservices, such as a product catalog service, a shopping cart service, and a payment service. Each microservice would be responsible for a specific function, and they would communicate with each other through APIs.

Containerization with Docker: Docker can be used to package each microservice into a separate container. This involves creating a Dockerfile for each microservice which contains instructions for Docker about how to build an image for that microservice. For instance, the product catalog service might have a Dockerfile that specifies the base OS, the version of Python or Java to install, any dependencies like libraries or frameworks, and the code of the service itself. When this Dockerfile is built using the Docker build command, it results in a Docker image, which can then be run anywhere Docker is installed, ensuring consistent behavior across different environments.

Orchestration with Kubernetes: Kubernetes comes in to help manage and scale these Docker containers. It can automatically distribute the load between containers, scale the services up and down based on traffic, and ensure high availability and fault tolerance. To use Kubernetes, you create configuration files, typically written in YAML, that define the desired state of your system - the services you want to run, how many replicas of each, how they should communicate, etc. Kubernetes then works to make the actual state of the system match the desired state. Let’s say your payment service is experiencing high traffic. If you’ve configured Kubernetes to auto-scale based on CPU usage or number of requests, it will automatically create more replicas of the payment service to handle the load. These replicas are distributed across different nodes (servers), ensuring that if one node goes down, the service can continue running on the others.

Linking Docker and Kubernetes: Docker and Kubernetes work together seamlessly. Kubernetes can pull Docker images from a registry like Docker Hub or Google Container Registry, and then run those images as containers. In our e-commerce example, once the Docker images for the product catalog service, shopping cart service, and payment service have been pushed to a Docker registry, Kubernetes can pull those images and run them as separate services. Kubernetes ensures that these services can communicate with each other and scale independently. This way, Docker and Kubernetes can greatly simplify the deployment, management, and scaling of microservices in a complex application.

When not to use microservices

For example, if you’re developing a simple application or a prototype, microservices may add unnecessary complexity. Similarly, if your application doesn’t require a high level of scalability or fault tolerance, microservices may not be necessary. Additionally, microservices can add additional overhead, such as the need for containerization and orchestration tools, which can increase development and deployment costs. Ultimately, it’s up to developers to decide whether microservices are the right fit for their specific application and business requirements.


Microservices Explained in 5 Minutes

Kubernetes vs. Docker