App & Data Integration 10 mins read

The Architecture of a Modern API Ecosystem

Uncover the layers and components of a modern API ecosystem. Build a robust and scalable API system that meets today’s digital demands.

Ann Marie Bond Ann Marie Bond

Since its conception, the modern API ecosystem has become much more complex and sophisticated to meet the increasing demands of today’s digital world. In their early days, APIs were relatively simple, often consisting of straightforward endpoints that clients could use to retrieve data, interact with each other, or perform specific actions. However, as the use of APIs has grown, so has the API ecosystem’s complexity. 

Today, API systems consist of many components and layers, each crucial in ensuring that the API works as intended. For example, an API system might include various APIs, different protocols and formats for transmitting data, and multiple tools for building, testing, and managing APIs.  

These tools range from API gateways for managing traffic and access to the APIs, an API management platform that provides utilities for developing, publishing, and governing APIs, to various other tools for specific tasks like authentication, authorization, and analytics.  

All these components are necessary to ensure that the API ecosystem is efficient and secure. This article provides an overview of the various components that comprise the architecture of a modern API ecosystem, including hardware, software, personnel, and layers.

API ecosystem architecture

It’s important to understand the architecture of a modern API ecosystem before constructing it because it helps you ensure the API system is scalable, secure, and easy to maintain. This makes it easier for developers to understand and use, which can drive adoption and encourage growth. That way, you can avoid the pitfalls of playing catch-up as the API evolves and instead focus on building a robust and sustainable API. 

Investing the time and effort in understanding the architecture of modern APIs ensures you can choose the appropriate technologies and tools to build and deploy an API that meets the needs of developers and users alike.

What is an API architecture?

An API architecture refers to the building blocks used to implement an API system. It consists of the API itself and several other components.  

An API architecture includes the complete solution from planning, designing, and developing the API interfaces to the surrounding infrastructure. It encompasses the network that enables the back-end data, services, and application functionality to be exposed to other applications in a reliable and scalable manner. In other words, an API architecture comprises the structure, components, layers, and infrastructure that support the API’s deployment and consumption.  

The architecture includes data storage systems that APIs use, the servers and networks that host them, and the client applications that interact with the APIs. All these elements work together to create a secure and efficient system for delivering APIs. This includes all the architectural decisions about the API system, such as design methodology, technical requirements, tiers, API lifecycle management tools, and other components necessary to support an API’s operation.

API ecosystem layers

An API ecosystem consists of several layers that interact logically to create a comprehensive API system. Each layer provides a standard set of functions that plays a specific role in the API ecosystem.  

API ecosystems typically contain many layers, including those discussed below.

Data layer

The data layer manages the storage, retrieval, and entry of data in the API system. This layer typically consists of data storage systems, databases, and the logic and algorithms necessary to manipulate and access the data through the API. The data layer ensures that data is stored and retrieved correctly and promptly delivered to the appropriate API components or consumers.  

This layer also implements validation and integrity checks, reduces latency by caching and indexing data, and along with data-minded architecture decisions, helps to ensure the API system can handle large volumes of data requests quickly and efficiently.

Application layer

The application layer contains the actual programming functionality, services, or business logic of the API system. It’s responsible for the implemented API’s exposed functionality and allows other applications to access and use the API’s capabilities.  

This layer handles the bulk of external calls and processes the API performs. It communicates directly with the data layer and — depending on the requirements — is frequently implemented as a decoupled microservice.

API gateway versus microgateway

An API gateway is an intermediate server between the client and the API system’s back-end services (application layer) as a gateway for accessing the API. It’s responsible for routing requests from clients to the appropriate back-end services, returning the response to the client, and handling authentication and other security measures.  

In a microservice architecture, it’s common to have many small, independently deployable services that work together to provide a more extensive functionality in an application. Each service typically exposes a set of APIs that other services and clients can use to interact with, enabling scalability, agility, and resilience. 

A central API gateway is typically required to mediate the public-facing APIs (also called north-south traffic) as a main point of entry for the system and enforces general security policies.  

However, the microservices working together to deliver an application can have lots of traffic between them (sometimes called east-west traffic) that also needs mediating. Due to this, the policy enforcement point (PEP) needs to be moved closer to the individual microservices to be able to enforce specific policies.  

A microgateway is a lightweight, decentralized gateway solution designed to address this issue. Instead of depending solely on a centralized API gateway, a microgateway can be deployed alongside the services to allow for policy enforcement in the same container as the microservice, providing more granular control over the traffic flowing through each service. At the same time, the microgateway communicates back to the main API gateway, which retains centralized control and visibility. 

The main difference between an API gateway and a microgateway is the degree of control and visibility. An API gateway is a full-featured centralized solution that provides a single point of control and visibility, allowing an organization to manage and monitor all API traffic from a single location. A microgateway offers more granular control and visibility, allowing you to have a decentralized solution for managing and enforcing policies in individual microservices.

Integration layer

The integration layer enables different software applications, services, and components to communicate and exchange data with each other, ensuring smooth delivery. This layer facilitates logical interactions between different applications to enable synchronous access to various services across the API system’s infrastructure. It does this by exposing services from other applications and translating the data and messages sent between the different applications so that each system can understand the other.  

The integration layer typically works manually, so it can be a time-consuming and error-prone process, especially for complex systems with many applications, services, and data sources.  

Software AG offers a robust, tightly formed API management solution that makes it easy to integrate different applications. Software AG makes the integration process quick and reliable by providing pre-built tools and functionalities that reduce the amount of custom code you need to write.

Interaction layer

The interaction layer is the point of contact between API layers (such as the application layer or data storage layers) and the clients that consume the API. It’s the topmost layer of an API system where customers, developers, and other users interact with the business logic applications and data made available through the APIs.  

It’s also where the API defines the specifications, methods, endpoints, rules, and protocols for how user applications can interact with the API, such as the specific formats and parameters in requests and responses. This layer typically includes everything between the different layers and the clients, including gateways, proxies, and load balancing.

API ecosystem services

To ensure your API ecosystem thrives in today’s fast-paced digital world, you need to employ value-added services like security, analytics, and developer support. 


Security is crucial to any API system because APIs are often used to transmit sensitive data and facilitate critical transactions. Without proper security, APIs are vulnerable to malicious actors that can access sensitive data or disrupt operations. 

It’s imperative to consider every aspect of the API ecosystem to ensure security, including the API itself, the servers and networks that host the API, the clients that access the API, and the data that flows through the API. These elements are all vulnerable to security threats. 

However, no security method is foolproof on its own. You should employ tools such as an API gateway, web application firewalls (WAF), standalone security products, or other API security precautions in your code.


Analytics gives you valuable insight into the API system, which can be useful for several reasons.  

First, it can help developers track and monitor their API use and identify potential problems in the API or areas where the API may not be meeting users’ needs.  

Additionally, monitoring API usage statistics can help you understand the popularity of your API and identify opportunities for growth or improvement.  

It can also help ensure the efficiency of an API ecosystem by giving your developers the information they need to optimize the APIs for performance.

Developer support

Providing strong developer support is another crucial part of ensuring that your APIs are successful and widely adopted by developers. This typically includes providing developers with documentation, guides, and other resources to help them understand how to use the API and integrate it into their applications. It can also include reference materials, code samples, and tutorials. 

With APIs having become products for most organizations, to succeed, they must be widely adopted by developers. A developer portal or API marketplace provides developers with a central hub or platform to access information, tools, resources, tutorials, and support for their development needs. It can also include related assets such as microservices, B2B integration, and integration connectors needed by the API. 

Additionally, developer portals offer a platform for developers to share their thoughts and best practices so that other developers can benefit from their experience. A developer marketplace can also help organizations gain more traction by promoting collaboration with bounded communities. These communities can include forums for feedback, the ability to share apps developers have built, and a customized UI. The main goal is to support the API’s development process by making it easier and faster to develop applications.


As the use of APIs has grown, so has the complexity of the API ecosystem. A modern API architecture typically includes several layers that work together to create a comprehensive API system and encompasses the various components and services that support the API’s deployment and consumption. 

An API system should be designed with security in mind and with measures in place to prevent unauthorized access, protect sensitive data, and guard against potential security threats.  

Check out Software AG and learn more about how our API management tool makes API management simpler and more effective.