Why Microservices Need an API Gateway


What Are Microservices?

Microservices (also referred to as the microservices architecture), involves a method of developing single, functional, and operational modules with interfaces when building software applications. They are characterized by features such as;

  • They can be deployed independently.
  • They are loosely coupled.
  • Can be tested and maintained easily.
  • A small team owns them.
  • They are organized based on the capabilities of a business.

Before enterprises started using microservices, they used to develop monolith applications. These are applications that were developed as a single unit. To make changes to their applications, they would often face a lot of challenges since a single change could affect the whole application. 

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To just change a piece of code, they would be forced to develop and deploy a completely new version of the application. It was also very difficult to add functionalities to parts of their applications without having to work on the application at large. With microservices, companies have been able to solve the problems exhibited with monolith applications.

Microservices use APIs to communicate and share information. This means that the growth of microservices is intertwined with that of APIs. A microservice architecture might come with multiple services, all working independently but to achieve the same goal. Here, API gateway programming creates an independent point of entry for customers, separating them from internal services.

How Microservices Benefit from API Gateway

1. API Gateway Allows Microservices to use a Mixture of Communication Protocols

If you look at APIs that have not employed an API gateway, you will realize that they offer REST or HTTP based communication protocols. However, this is different for microservices that have deployed an API gateway.

The API gateway offers a unified and external API based on the REST architecture across multiple communication protocols such as AMQP, ProtoBuf, and integrations with JSON-RPC, XML, and SOAP. This gives development teams a chance to choose the communication protocol that best works for them.

2. API Gateway Helps to Prevent External Clients from Accessing Internal Concerns

With an API gateway, enterprises are able to separate internal microservices from external access by customers or even public APIs. This makes it possible for developers to easily add microservices without having to worry about boundaries with external access.

This way, as time goes on, they can refactor new microservices without affecting external clients in any way. The external clients get a single entry point making sure that no matter the number of versions a microservice has, they will not notice, and service delivery will remain the same.

3. Limiting Complexity with Microservices

As explained above, microservices are composed of single functional and operational modules with interfaces. When building microservices, developers might be forced to add things such as rate-limiting, authorization, or even access control. 

If one wants every module to implement them, it would mean that they would spend a lot of time before they can come up with the complete systems. However, employing an API gateway eliminates these issues, making sure that the microservices do what they are supposed to do.

4. Addition of a Security Layer

Security is an integral part of microservices. A security leak might affect the entire operations of the services bringing businesses to a halt. However, an API gateway can help one avoid security leaks by adding a new layer of security that helps to avoid DoS attacks, SQL Injection, and other forms of attacks.


Microservices have made the development of systems easier. They (together with APIs) are the reason IoT companies are growing fast. However, implementing them without an API gateway means that one is exposing their work and communication to external access. This shows that it is very important to think about an API gateway when working with microservices.

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