With the trend toward cloud-native and microservices in software development, API-first design is more important than ever. APIs are the key to tying all those modular components together. They give your internal developers a reliable way to build extensible, reusable software applications that scale. Building API-first products and services ensures more businesses can integrate your products into their ecosystems. APIs also make it possible to reach millions more customers than you could without them.
API-first design is as much a set of principles as it is a group of technologies, tools, and programming languages. When you get APIs right, you simplify software development, speed up delivery, and future-proof your organization for changes in customer and market behaviors. Here’s everything you need to know to get started with API-first design at your company.
What is API-first design?
API-first design is an approach to software development where the Application Programming Interface (API) is treated as the primary component of the application. The idea is to design, build, and test the API before developing the user interface or other aspects of the application. This approach encourages developers to think about the API as the core of their application and prioritize its development.
API-first design places the API at the heart of your software development, ensuring a robust, well-documented, and easy-to-use interface that provides access to the underlying services and data. This allows multiple applications or services to interact with the system through a common interface. That makes it easier to maintain and evolve the system over time.
While APIs depend on a wide array of technologies and skill sets, there are principles every DevOps org needs to practice.
Eight key principles of API-first design
Put this list on Notion or print them out for the daily Scrum. They’ll become like second-nature once you and your team work them over time. But if you’re just getting started, take a page from Lean/Six Sigma and make them easily visible until everyone understands the approach.
- Prioritize the API – Design the API before starting on any application or user interface development. This ensures it’s the project's central focus and defines a clear separation of concerns to enable better collaboration between teams.
- Define API contracts clearly – Define the API contract as early as you can. This is a detailed specification of the API's functionality – including the endpoints, request/response formats, and expected behaviors. Specify the API's inputs, outputs, and behavior using a formal API specification language like OpenAPI or RAML. This contract guides developers and ensures consistency across different parts of the application.
- Use standardized design practices – Follow standardized design practices (like REST or GraphQL) to make the API more predictable and easier to understand for developers.
- Build for scalability – Design the API to support future growth and additional features. Each API must be ready to scale and evolve without knowing specific future requirements.
- Focus on documentation – Provide clear, concise, and up-to-date documentation for the API that includes examples and tutorials. This makes it easier for developers to understand and use the API effectively.
- Design for reusability and extensibility – Create modular and well-organized API endpoints that can be reused across multiple applications or services. Ensure they can be easily extended to accommodate new features or changes in requirements.
- Implement a robust testing strategy – Develop comprehensive tests for the API to ensure that it behaves as expected and adheres to its contract. This can include unit, integration, and end-to-end tests, as well as performance and security testing.
- Versioning and backward compatibility – Plan for API versioning and maintain backward compatibility whenever possible. This minimizes disruptions for the applications or services using the API.
Global companies and products that use API-first design
APIs power the most popular digital services – Google Maps, payment platforms like Stripe and Paypal, communication tools like Slack, and generative AI solutions like ChatGPT built on OpenAI’s API. These products were built with an API-first design that makes them accessible and usable by senior software engineers and developers worldwide.
Because of that, they’re widely adopted by other businesses and integrated into tens of millions of people’s daily lives.
- Google Maps — Google Maps API allows developers to embed maps, search for locations, and calculate directions within their own applications. This API has been widely adopted across various industries, powering location-based services and apps.
- Stripe — Stripe is a payment processing platform that offers a suite of APIs to help businesses accept and manage online payments. Its API-driven approach makes it easy for developers to integrate secure payment processing into their applications. APIs are crucial to Stripe’s widespread adoption.
- Twilio — Twilio is a cloud communications platform that provides APIs for developers to integrate messaging, voice, and video communication into their applications. This company exists solely because of how vital APIs are. It allows businesses to build custom communication solutions tailored to their specific needs.
- Slack — Slack provides APIs that allow developers to create custom integrations and bots to enhance the platform's functionality for their team’s specific needs. APIs make Slack an extensible and flexible solution for team communication and collaboration – a critical part of why it’s so widely used.
- ChatGPT – The fastest adopted application ever, ChatGPT is powered by OpenAI's API for Large Language Models (LLMs). Developers worldwide can use the OpenAI API to build their own LLM and natural language processing (NLP) solutions. By leveraging OpenAI's API, developers can create a wide range of applications and services to perform tasks like text generation, summarization, translation, question-answering, and more.
While these are very different products and services for the end users, the underlying technology that builds the APIs are very similar.
What are the technologies and tools that make API-first design possible?
These globally adopted tools rely on some of the same foundational technology. APIs can be built in a few ways, but developers always need tools to design, build, document, test, and manage APIs effectively.
- API specification languages – These allow developers to define the API's structure, inputs, outputs, and behavior in a standardized way.
- OpenAPI Specification (formerly Swagger) – Widely used and popular API description language to describe RESTful APIs.
- RAML (RESTful API Modeling Language) – Another API description language focused on modeling RESTful APIs in a simple and easy-to-read format.
- API design tools – Tools that assist in designing, visualizing, and prototyping APIs that support API specification languages.
- Swagger Editor – Open-source editor to design and document APIs using the OpenAPI Specification.
- Postman – Popular API development and testing tool that supports designing, documenting, and testing APIs in one platform.
- Apiary – Collaborative API design platform that supports API Blueprint and OpenAPI Specification.
- API documentation tools – Tools that generate and maintain API documentation based on the API specifications.
- Swagger UI – Generates interactive API documentation from an OpenAPI Specification, allowing developers to explore and test the API.
- ReDoc – Open-source tool that generates responsive and customizable API documentation from an OpenAPI Specification.
- Slate – Static site generator that produces clean, responsive, and customizable API documentation from Markdown files.
- API testing tools – Tools that enable developers to test their APIs for functionality, performance, and security.
- Postman – Postman also supports API testing. That includes automated testing with its built-in scripting language.
- SoapUI – Widely used open-source tool for testing both RESTful and SOAP-based web services. Supports functional, performance, and security testing.
- JMeter – Open-source performance testing tool that can also be used to test APIs. Especially useful for load and stress testing.
- API management platforms – Tools that help manage the entire lifecycle of an API – from design to deployment. They also provide features like access control, rate limiting, and analytics.
- Apigee – Comprehensive API management platform by Google that provides tools for designing, securing, and analyzing APIs.
- AWS API Gateway – Fully managed service by Amazon Web Services that enables developers to create, publish, and manage APIs.
- Kong – Open-source API gateway and platform that helps manage APIs and microservices. Supports authentication, rate limiting, and more.
CIOs look for these benefits of API-first design
API-first design comes with benefits for every layer of your company – from DevOps to marketing operations. Overall, your CIO will care about these strategic returns from prioritizing APIs in software development:
- Faster time-to-market – API-first design enables your company to develop and release new features, products, and services more quickly. This comes from the reusability, standardization, and modular capabilities you get by centering APIs.
- Scalability and flexibility – The API-first approach supports the adoption of microservices and cloud-native architectures. Getting APIs right is often the missing link to help organizations scale applications efficiently and adapt to changing requirements fast.
- Interoperability and integration – API-first design facilitates seamless integration with internal systems and third-party services. This lets you leverage existing investments and access new capabilities easily.
- Enhanced collaboration – API-first design encourages collaboration between development teams, stakeholders, and external partners by creating a shared investment in focusing on the API.
- Innovation and business opportunities – Your company can create new revenue streams and business opportunities by exposing APIs to external developers and partners. This ultimately drives ecosystem growth and innovation.
- Cost reduction and resource optimization – API-first design often reduces development and maintenance costs by promoting reusability, modular architecture, and improved collaboration. This lets leaders optimize their resources and focus on strategic initiatives.
- Security and compliance – API-first design emphasizes security best practices and helps ensure compliance with industry standards and regulations. This reduces potential security vulnerabilities by using APIs as a well-defined interface for accessing data and services.
- Improved customer experience – By implementing API-first design, your company can deliver a more consistent and reliable customer experience across various channels and touchpoints.
Short list to get started with API-first design
API-first design isn’t a once-and-done kind of initiative. You need to get everyone from your senior software engineers (that won’t be a hard sell) to your business partners on board with a new approach.
Once you build a foundation for API-first design, you'll be developing and thinking in interchangeable, reusable, and scalable systems as you grow. Here’s a list of basic steps to get started.
- Establish a cultural understanding – Educate your development and business teams on the principles and benefits of API-first design. This is crucial to foster a shared understanding and commitment to the approach.
- Choose the right tools and technologies – Leverage tools and technologies that support API-first design. Lean into API specification languages (e.g. RAML), design and documentation tools (e.g., Swagger, Postman, Apiary), and API management platforms (e.g., Apigee, AWS API Gateway, Kong).
- Define API standards and guidelines – Develop organizational API standards and guidelines that outline best practices for designing, documenting, testing, and managing APIs. This helps ensure consistency and quality across all of your APIs.
- Encourage collaboration – Facilitate collaboration between development teams during the design phase and the entire API lifecycle. Encourage sharing knowledge, feedback, and lessons learned to promote continuous improvement.
- Monitor and measure – Track the performance and usage of your APIs to identify areas for improvement, optimize resource allocation, and inform future API development efforts.
How do I find someone who already builds API-first?
You might not have a team who can switch your whole company over to an API-first way of designing, building, and maintaining software. And it could take 6-18 months (or longer) to hire an internal team that’s ready to dive into APIs. Not a problem. That’s why Codingscape exists – we can help you get started with API-first design and build software with you by next quarter.
We get up to speed faster than other firms (or internal recruiting) to start delivering software you need. Zappos, Twilio, and Veho are just a few companies that trust us to build software. You can schedule a time to talk with us here. No hassle, no expectations, just answers.
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Cole is Codingscape's Content Marketing Strategist & Copywriter.