Everything You Need to Know About API Development: A Comprehensive Guide

Modern software rarely works in isolation. Instead, it uses APIs to communicate with other apps, platforms, and services, saving developer resources and time. No wonder that this tech is gaining traction among developers — 81% of them rely on API development more than ever before.

In essence, APIs, or application programming interfaces, connect different software systems and let them share data and functionality. As a leading API development service provider, GoodCore will tell you everything you need to know about these solutions. Discover the benefits, challenges, and the API development process itself in our guide.

What Is API Development?

An API is a set of rules, standards, and protocols that lets different applications interact with each other, hassle-free. The apps can request and exchange information, as well as use each other’s features and services.

To put it into perspective, imagine you’re building a fitness app. You want to offer users the ability to track their running routes. Instead of creating your own complex mapping system, you can use an API from a popular navigation service, such as Google Maps. Through this API, your app gets access to real-time location data and your users effortlessly track their runs on a map.

API development, in turn, is the very process of creating and maintaining APIs. It involves specifying endpoints and data formats, implementing authentication and security methods, and ensuring efficient performance through testing.

It’s possible to build different types of APIs. In particular, GoodCore highlights and is experienced in the following options:

• REST APIs. Widely used, simple, and scalable; rely on HTTP methods.
• SOAP APIs. Rigidly structured and highly secure; use XML.
• GraphQL APIs. Relatively new but rapidly growing; lets developers request only the necessary data in a single query.
• WebSocket APIs. Best for real-time data transfer; enable two-way communication.

Main Types of APIs You Should Know

While we covered the API basics above, let’s explore further. Here are the most common types of APIs, each suitable for specific needs and use cases:

REST APIs

REST (or RESTful) APIs are a popular and widely adopted architectural style. They leverage standard HTTP methods (GET, POST, PUT, DELETE) for data manipulation and retrieval. Known for their simplicity, scalability, and reliability, REST APIs are perfect for web services and mobile apps.

Typical use cases include:

• Web apps
• Mobile apps
• Integrations
• Internet of Things
• Financial services
• Cloud services
• Content management systems

Key features:

• Stateless. Each request-response interaction is independent, meaning the server doesn’t store information about previous requests.
• Layered. You can structure REST APIs with multiple layers, each with its own functionality or service.
• Resource-oriented. APIs focus on accessing and manipulating resources identified by URLs.

SOAP APIs

SOAP (Simple Object Access Protocol) APIs use a strict, XML-based protocol for communication. This makes them best for enterprise-level applications where security and reliability are a must.

Typical use cases include:

• B2B integrations
• Financial services
• Telecom
• Web services
• Legacy systems

Key features:

• Structured data exchange. SOAP uses XML messages to define data formatting, transmission, and processing.
• Enterprise-focused. SOAP’s structured nature makes it well-suited for complex data exchange often seen in enterprise applications.
• Platform-independent. You can use SOAP APIs to enable communication between apps on different OSs and programming languages.

GraphQL APIs

GraphQL is a data query language for API development. Here’s what makes it special. Unlike REST APIs, which select predefined data structures, GraphQL allows users to specify the exact data they need and receive it in a single request. This makes GraphQL APIs more flexible in terms of data manipulation.

Typical use cases include:

• Complex user interfaces
• Mobile applications
• Single-page applications
• Third-party integrations

Key features:

• Query language. Developers select and get the required data in one request, without making multiple calls.
• Flexible data retrieval. A single request can retrieve data from multiple resources within the API.
• Improved developer experience. The GraphQL queries’ clear structure and flexibility simplify development and maintenance for complex data interactions.

WebSocket APIs

WebSocket APIs differ from the previous API types as they set up a persistent, two-way communication channel between the client and server. Hence, they allow for real-time data exchange, perfect for apps that need constant updates — think live chats or online games.

Typical use cases include:

• Streaming services
• Internet of Things
• Collaborative editing tools
• Real-time analytics tools
• Chat applications
• Online games

Key features:

• Bidirectional communication. Data can flow in both directions simultaneously between the client and server, enabling real-time interaction.
• Lower overhead. Compared to traditional HTTP APIs, WebSocket offers a more efficient way to handle real-time data updates.
• Persistent connection. The connection between the client and server remains open, which enables continuous, real-time data exchange.

Want to learn more about different types of APIs? Check out our latest post on third-party API integration in healthcare apps.

Benefits of API Development

Before we explore how to build an API, let’s figure out what for. The reasons you may want to jump into custom API development or integrate existing APIs with your app include the following:

• Improved connectivity. APIs bind different apps and services together and set standards for data formats, creating a more cohesive ecosystem.
• Enhanced functionality. APIs let you pack your app with cutting-edge features without reinventing the wheel. You can leverage existing (and time-tested!) solutions like social media, weather services, or navigation systems to enrich your application’s capabilities.
• Better integration between systems. APIs connect disparate apps seamlessly, even when dealing with different operating systems, programming languages, or hardware infrastructures.
• Improved scalability and performance. Well-designed APIs can handle increased traffic and provide you with the means to scale as necessary.
• Increased product value. Handling API development and integration allows you to offer more value to your users. You can implement the features your audience begs for, significantly outperforming your competitors.

But there’s always a ‘but.’ To achieve the above advantages from APIs, you should build them with a well-thought-out plan in mind. Luckily, GoodCore can help you out. Choose our API development services to get robust and reliable solutions tailored to your goals.

API Development Process Step by Step

Building a successful API isn’t just about code. It’s a process that requires careful planning, thorough testing, and ongoing support — at least, that’s what our team considers non-negotiable. So, here’s how to build an API from scratch in several steps:

Planning and Design

Before writing a single line of code, you need to have a plan. At GoodCore, we closely collaborate with you to learn your business goals, target audience, and the API’s intended use. We’ll work with you to:

• Define API scope and functionality
• Choose a suitable API type
• Design a user-friendly API architecture

Development

With a solid plan in place, we translate that vision into code. Our API software development covers implementing the necessary functionality, security measures, and access controls — all with scalability and performance in place.

Testing

Just like any software, APIs need rigorous testing before deployment. GoodCore uses the following testing methodologies to ensure your solution is secure, reliable, and performs well:

• Unit and functional testing. We check all API endpoints to make sure they work as intended.
• Integration testing. We test how your API interacts with other systems and applications.
• Security testing. We handle security tests to find and solve any vulnerabilities in your API.

Deployment

Once we test your API, it’s time for deployment. As part of this process, we handle:

• Deployment environment selection. We choose the most suitable deployment environment based on your needs, whether cloud-based hosting or on-premises infrastructure.
• Actual deployment. Our team deploys your API to the chosen environment.
• API documentation. We create crystal-clear documentation with described API calls, use cases, error codes, and code snippets, so you can understand your API in depth.

Maintenance and Support

Even after deployment, we keep improving your API. Here’s what we typically do at this point:

• Bug fixes and security updates
• Performance monitoring
• API versioning and updates

API Development Tools

Learning how to build an API platform requires more than just exploring the main development stages. You also need the right tools to handle the job. Here’s the selection of those that our team frequently uses:

API Design Tools

The tools you can use to design your API include:

• Swagger is a complete API editor that lets you design, document, and test your API.
• Postman is a tool for designing, building, and testing APIs. It also allows you to create documentation and collaborate on your APIs.
• Insomnia, another popular API design tool, offers features for designing, mocking, and testing APIs.

Development Frameworks

Once you complete the design, you can start developing APIs using the following frameworks:

• Django. This Python-based high-level framework lets you build secure and scalable APIs.
• Express.js. Based on JavaScript, this framework is best for developing lightweight and efficient APIs.
• Flask. One more popular Python framework, Flask, offers a minimalist approach to API development, allowing engineers to focus on essential features.

Testing Tools

You can test the developed API using the following tools:

• JUnit. This tool is suitable for unit testing of your API.
• Pytest. A versatile testing framework, Pytest lets you test Python-based APIs.
• Newman. This command-line collection runner is used to test APIs designed by Postman.

Monitoring and Analytics Tools

After deployment, you should keep monitoring your API’s performance. Here are several tools for this:

• New Relic. This platform allows you to monitor your entire stack, from logs and security to system health.
• Splunk. This tool, best for enterprises, offers AI-powered solutions for observability and security.
• Datadog. Similar to New Relic, this platform provides detailed insights into your API performance.

GoodCore’s Best Practices in API Development

To deliver reliable, future-proof solutions, our API development company applies several best practices. Consider those when working on the product of yours.

Security

API process development begs for security, given the amount of data involved. We ensure API protection through several means:

• Authentication and authorisation
• Data encryption
• Regular security testing

Documentation

In our work, we emphasise clear API documentation. That’s because it can make or break your API usage and integration efforts. To ensure the documentation is detailed and straightforward enough, we clearly define endpoints and functionalities, include code samples and use cases, and provide a list of potential error codes and how to interpret them.

Versioning

APIs typically evolve alongside your business and the changes it experiences. Versioning lets you introduce these changes while staying compatible with existing integrations. To manage API versions, GoodCore develops a clear versioning scheme that distinguishes different API iterations.

Scalability

Same as with changing business requirements, your user base may expand. That’s why ensuring scalability is a top priority for us. We optimise code and use throttling to make sure your API is scalable.

Common Challenges in API Development and How to Overcome Them

API development comes with its own challenges, but with the right strategies and expertise, they can be managed easily. Here are some common obstacles you may face and how GoodCore tackles them:

Security Issues

According to the State of API Security Report 2024, 95% of companies experienced some kind of security issues in their APIs. Typical problems include injection attempts, unauthorised access, and man-in-the-middle attacks. To address these, we use input validation techniques, multi-factor authentication, and secure communication protocols.

Performance Bottlenecks

APIs with inefficient code are slow and frustrating. The same applies to those solutions that cannot scale properly and handle unexpected traffic spikes. Luckily, we design with scalability in mind, ensuring your API delivers a fast and responsive user experience, even under heavy loads.

Integration Difficulties

When integrating an API with your other systems, you may face difficulties due to incompatible data formats and limited technical resources. We tackle this by transforming data into a unified format and providing you with detailed API documentation.

Documentation and Usability

Finally, you may find it hard to use an API if its documentation is filled with technical jargon, lacks code samples, or is outdated. Our team delivers only well-documented APIs and constantly updates the knowledge base whenever changes are made.

Why Choose GoodCore for API Development?

For almost 20 years in the market, GoodCore has been consistently delivering reliable APIs and software to clients. Our success wouldn’t be possible without following our steadfast principles:

• Security is a priority
• Clients are at the centre of our work
• Scalability is a must

Besides, we emphasise expertise and constant growth. Our team is well-versed in REST, SOAP, GraphQL, and WebSocket APIs and provides solutions for various industries, with healthcare, education, and SaaS being just a few. Our offerings include:

• Enterprise system integration
• Data integration
• Third-party API integration
• Custom API development services

Learn more about what we can do for you by viewing our recent API development case study.

GoodCore’s API Development Success Story

Our healthcare client, CoolCare4, needed an API that would bring together all their data from various sources in a single place. We had to connect information from multiple care homes, including details about the homes themselves, their staff, and the residents.

To handle all of this, we wrote complex SQL queries tailored specifically to what our client needed. Security was another concern, so we included solid authentication and authorisation mechanisms. 

As a result, the API we built allows for easy information retrieval and updates across all these databases.

Conclusion

API development is the first step in building a hyper-connected world. It allows your app to easily exchange data with other systems and deliver robust features to your users.

Yet, building a successful API requires expertise and a well-thought-out plan. Luckily, GoodCore can help with that. If you want to know how long does it take to build an API or have any other questions left, contact our team for in-depth consultation. Let’s discuss how APIs can transform your business together.

FAQs

What are the key stages of API development?

The API development process at GoodCore consists of the following stages:

1. Planning and design
2. Development
3. Testing
4. Deployment
5. Maintenance and support

What are some API development best practices?

The best practices in API development that we apply cover four main areas: security, documentation, versioning, and scalability. That means we focus on robust security measures, develop comprehensive API documentation, create a clear versioning scheme, and design scalable API architectures.

How do different API architectural styles compare, and which should I choose?

The main styles of API architecture are REST APIs, SOAP APIs, GraphQL APIs, and WebSocket APIs. Each solution offers distinct strengths for specific use cases. REST is the best choice for a simple and scalable API. If you need robust security, select SOAP. GraphQL is perfect for complex user interfaces, while WebSocket is a decent option for real-time data exchange.

What should comprehensive API documentation include?

API documentation created by GoodCore includes descriptions of API endpoints and functionalities, code snippets, and error codes, along with clear examples and use cases.

How can I ensure my API remains compatible as it evolves?

To ensure compatibility, the best API development companies leverage versioning systems, establish deprecation policies, and maintain backward compatibility.