What is API Design (And Why Does It Matter?)

  September 27, 2016

Building APIs is hard. Apart from long meetings with business stakeholders, choosing the right technology stack, and building an appropriate data-distribution model, there are a lot of finer details that can get overlooked. After the great API movement of the 21st century with the advent of social media and the explosion in mobile technology adoption — organizations have realized the growth opportunity APIs present.

But be careful with your APIs. An API can be your best friend but also your biggest liability. A bad user experience while consuming your APIs will lead to an endless queue of support calls followed by bad reputation, which is all that it could take to make your sevices unreliable. So it’s important to plan, plan, and plan even more before you actually go out and start to implement your API. This is where design and the amazing prowess of RESTful API description formats like the OpenAPI Specification and API Blueprint come into the picture.

Defining API design

When I first heard the term, I thought it meant writing the syntax and code in such a way that it’s aesthetically appealing. While that’s part of it, API design involves a lot more than the way you write your syntax. Designing an API means providing an effective interface that helps your API’s consumers better understand, use and integrate with them while helping you maintain it effectively. Every product needs a usage manual, and your API is no exception. API design should encompass:

  1. The structure of resources
  2. The documentation of your resources

There are a host of good practices associated with the above, which I will cover in the subsequent blog posts. For now, let's start with understanding the importance of why your API should have a great design.  

Helps in better implementation

An API’s design is a solid blueprint on what your API wants to achieve and gives a comprehensive overview on all the endpoints and CRUD operations associated with each of them. An effective API design can greatly help in implementation and prevent complicated configurations, adherence to naming schema within classes, and a host of other issues that can keep you up for days. The design process will also help you think through exactly how your data will be distributed and how your core product will work.

Facilitates incremental development

API development is a continuous process. Any company that thinks otherwise is not taking advantage of the full potential of what an API can do. As your products and services evolve, so should your API. Having a clear design helps your organization and team know exactly which resource, or sub-resources, would need to be updated, preventing confusion and chaos.. The bigger the API is, the harder it can be to manage it. A well designed API can prevent repeating work and help developers know exactly which resources would need to be updated and which ones should be retired.   

Facilitates better documentation

Documentation is crucial for building the interface that lets your API be consumed. In many cases, comprehensive documentation is done only after the API’s resources and response-request cycles are mapped out. A solid initial structure makes documenting the API faster and less error prone for the people responsible for handling documentation. The documentation process can be more self-optimized with a great design to build a comprehensive interface on top of.  

Improves Developer Experience

Developer Experience (DX) is crucial. If you’re a developer, chances are you’d have had to work and integrate with a service which made you want to break your computer. We’ve all experienced that one web service which had us spend countless hours on StackOverflow and Reddit trying to figure out just how to use it. A good API design makes the life of the end developer easy. It’s quick to understand with all the resources well organized, fun to interact with and easy on the eyes, so the people who consume your API have a flawless experience working with it.


Good API design improves the usability of your API, resulting in higher adoption, less headaches, and an overall better chance of success for your API endeavors. While I’ve laid out the importance of API design, putting this is practice can be hard. Efficient design takes practice. In my upcoming blog posts, I will try to lay out some good practices while designing your API.

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