API-led architectural approach

API-led, API-first, and the API economy are all mantras that bring to the forefront that APIs are key implementation strategies for digital services. These are all architectural approaches that center around APIs as the mechanism to communicate between applications and business services that result in revenue. APIs provide an invisible delivery functionality that allows applications to run across all digital channels (as noted in the Hybrid reference architecture section).

An API is an API is an API. Yes, in general, that is correct, but the placement and responsibilities of an API may change. Let's explore these differences.

API flavors

APIs are developed in different flavors, with each for a different target audience. When you learn about API Connect, it will be beneficial to understand the different types of APIs you may need to manage and/or interact with. We will use the hybrid reference architecture to help label the different types of APIs:

Figure 1.5 – API-led flavors

As you can see, there are four types of APIs. The following is a brief description of each:

Table 1.1 – API types based on where they're utilized

Our primary focus will be developing process/interactive APIs when we are working with API Connect. Although API Connect has Node.js capabilities to create backend APIs, we will not be showing you how to code with Node.js. There are many other resources available to help you with that. You can start learning about Node.js by going to https://nodejs.dev/learn.

If we return to our digital framework categories, the following diagram highlights the specific points that can be accomplished using API Connect:

Figure 1.6 – API Connect supported technologies

As you can see, the table has highlighted the majority of the goals. When you look at the Customers column, you can see that you can provide consumers with the ability to subscribe to and create UX APIs/applications for multi-channel devices. API Connect provides you with the ability to engage with consumers using the Developer Portal. The Developer Portal has built-in capabilities to interact with social media applications. It lets you start forums and allows the company to add customer support (FAQ and Contact Us). As added benefits, analytics is provided to the consumers to show how well their apps are performing.

As we mentioned earlier, you can include operational capabilities (such as automatic deployment and testing), improved performance within the gateway runtimes, and the ability to share APIs between consumers and internal teams.

Your responsibilities for APIs

Now that you understand what an API-led architecture is and the types of APIs, you will have to consider the following responsibilities and address them:

• Securing APIs from unauthorized access (OAuth, JWT, and others).
• Defining security authentication/authorization for backend systems.
• Ensuring that consuming applications are routed to the appropriate API endpoint.
• Setting a rate and burst limit to limit the number of calls that are made to an API.
• Error handling with catch blocks and preventing error propagation to the backend.
• Begin working on using the API Connect capabilities for life cycle management, CLI interaction for future DevOps integration, and generating unit tests for deployment.
• Documenting your API so that consumers can quickly adopt your services.

So, you might be wondering where digital modernization fits in. You will learn about this next.