For Developers

Application Programming Interface: Design, Features, and Functionalities

Application Programming Interface: Design, Features, and Functionalities

Application programming interface (API) is one of the most vital components of application development and software systems. API is primarily used for simplifying software development and enabling data exchange between applications through seamless integration. Its major functionalities include organizing code, hiding complexity from the developers, ensuring reusability of components, and extending systems for development.

The application programming interface enables products and services to interact, thereby harnessing each other’s functionality and data via a structured interface. The use of API has multiplied in the last few years. Today, some of the most popular web applications utilize APIs to create dynamic functionality based on custom business requirements. Before we discuss different aspects of the application interface, we will first have a broader look at what an API is and how it functions.

How do APIs function?

API refers to Application Programming Interface, and it is a set of tools for interacting with different internal and external software components. The application programming interface serves as a link between the application and the webserver. It is essentially an intermediary layer responsible for processing data transfer between the different systems and system modules.

  • First, the client-side application initiates the API call for retrieving the information, and this process is also called a request. The application sends this request to the web server through Uniform Resource Identifier, and this request contains various elements, including a verb, header, and request body.

  • Once the request is received, the API is responsible for making the call to the web server or an external program.

  • The server then sends the relevant response to the application interface.

  • Finally, the API transfers that data to the client-side application that made the request.

The API protocols

Since the use of APIs in web applications has become prominent, several protocols have been introduced for outlining the acceptable commands and data types. These protocols provide the underlying standards for exchanging data and information between the different software applications. Some of the major application programming interface protocols used in the industry include SOAP, REST, JSON - RPC, and XML - RPC. Let us have a brief look at these different API protocols.

  • SOAP: The SOAP stands for Simple Object Access Protocol, and this protocol is built using XML This protocol enables users to share data via HTTP and SMTP. The SOAP API makes it convenient to share information between the different software modules and apps written in varying languages or that run in different environments.

  • REST: Representational State Transfer (REST) provides architecture principles for web API and it adheres to the REST architectural style constraints which enable communication with the RESTful web services. This is a set of architectural rules that underlines the interaction with web services. The RESTful APIs can be built using SOAP protocols, but these two standards are often perceived as competing stipulations.

  • JSON - RPC: This protocol uses JSON for remote procedure calls to transfer data between the different modules. There might be other parameters within the call based on the users' requirements.

  • XML - RPC: This protocol uses the XML format for transferring data in contrast to SOAP which uses the proprietary XML format. The XML - RPC provides a simpler implementation and it is also comparatively lightweight since it utilizes minimum bandwidth.

Different types of APIs

The four fundamental types of APIs that are used in web apps and different applications include Open APIs, Partner APIs, Internal APIs, and Composite APIs. We will have a brief overview of each of these API types.

1. Open APIs

Open APIs are open-source application programming interface modules that any developer can access. Since these are open-source interfaces and are freely available to anyone, they have lower authorization requirements and are limited in terms of assets that they can share. Some APIs are completely free, whereas others are available on a subscription fee basis. The open APIs allow third parties to harness their data and functionality.

2. Partner APIs

The partner APIs are application programming interfaces that are shared externally with business partners. The access to these APIs is restricted to only authorized stakeholders having official licenses. This provides a higher layer of security in comparison to the public APIs.

3. Internal APIs

The Internal APIs are interfaces that are only available for internal users and are concealed from the third party or external users. These APIs are only accessible within the company framework and are designed for streamlining the transfer of data between systems and cross-functional teams. The data transfer using internal APIs is more secure and efficient in contrast to the public APIs.

4. Composite APIs

The composite APIs are made up of various APIs. This enables the developers to package their requests or calls to receive a singular unified response from various servers. The composite APIs provide an ideal solution when you need data from multiple servers or endpoints within a single call. The composite APIs are particularly helpful in the microservices architecture, as you need data from various sources for performing a single task. Due to their inherent nature of functioning, the composite APIs reduce the influx of API calls resulting in less server load, which contributes to faster systems and overall greater efficiency.

API security

The security of the APIs is very important since they are responsible for connecting two different components of applications and thus can be vulnerable to potential outside threats. This is why the calls made by API consist of authorization credentials for minimizing the threat of security attacks. The APIs also use cookies, string parameters, or HTTP headers to provide additional security layers to the transfer of data and communication.

One of the common examples where application programming interface security is significantly important is the online payment processing services. These services deal with critical data including payment and banking information so ensuring data encryption for preventing data breaches is crucial.

The payment processing involves end-users inputting payment information at the application front end. The API then creates a unique token for the transaction and this token is included in the API call that goes to the server. This mechanism ensures that a robust layer of security is established for protection against potential threats or attacks.

Benefits of APIs

There are a host of benefits provided by the different APIs to developers when interacting with various software modules and applications. Some of the prominent advantages include improved collaboration, abstraction, higher productivity, increased security, and monetization options. We will provide a brief overview of each of these benefits.

Improved collaboration

The enterprises use a wide range of cloud applications and interact with various external modules to provide an efficient business framework. The integration of relevant application programming interfaces between these applications and modules enables seamless communication and streamlines the entire business process. Using this effective integration, the enterprises can deploy automated workflow thus improving the collaboration in the workspace.


The APIs provide one of the most foundational concepts in software systems known as abstraction. The abstraction is nothing but a way of hiding system complexity, enabling users to perform simple actions on top of complex architecture. One of the common examples of system abstraction provided by APIs is the dashboard buttons. The dashboard button encompasses a complex set of functionality behind its simple and easy interface. When you use the dashboard button for ordering a product, for example; it unleashes a chain of events behind the scenes including communication, authentication, and validation functions before your order is confirmed. The APIs are a critical component for providing convenient business solutions to the end-users.

Higher productivity

The APIs provide flexibility for enterprises to establish connections with business partners, launch new services and products for the existing market, and eventually explore new opportunities for scaling the business operations and driving the new wave of digital transformation. The APIs, thus play a major role in boosting the productivity of businesses and paving the way for better collaboration on high scaling projects.

Increased security

The APIs deliver an added layer of security for data communication between the servers. The security can be further enhanced through the use of signatures, transport layer security encryption, tokens, and the implementation of API gateways for authenticating traffic.

Monetization options

While many APIs are available for free, there is huge potential for monetizing the development of different APIs. If your API provides high value to the digital assets, there is an option of monetizing it by selling its access and functionality to the developers. For instance, AccuWeather sold a wide array of API packages and API keys to thousands of developers thereby establishing a collaborative community of developers.

The APIs are prominently used in almost all the software modules today and thus it is crucial to have highly skilled API developers for building your modern applications. You can hire top API developers at Turing through a seamless and effective process.

Prominent API examples in the industry

The APIs have become one of the most valuable digital assets for leading companies in the software industry. Some of the prominent examples of efficient APIs in the industry include Google APIs, Twitter APIs, and Java APIs among others.

  • Google APIs: The Google APIs connect the code and the entire array of Google services, ranging from Google Translate to Google Maps. Google Maps is an excellent example of a Google application programming interface where it uses core APIs for displaying interactive and static maps. Beyond that, it uses other APIs for offering directions and other features to the users. The multiple data layers and geolocation information bundled in with the APIs provide a comprehensive range of Map features and functionalities to the users.

  • Twitter API: Twitter API is built using web-based JSON API technology and it enables the developers to communicate with Twitter data. It is a web-based API feature and it can be accessed by sending requests to services that are hosted by Twitter, over the network. For accessing the functionality of the Twitter API, the application sends the HTTP request and the server returns a formatted response that applications can easily parse. Twitter uses a popular format in the form of JSON for delivering the responses to the client requests.

  • Java API: The Java API consists of a library of software modules and components that are available to anyone with access to the Java Development Kit (JDK). These components provide integration of common functionalities for increasing productivity as developers don’t need to code everything from scratch. The List is one of the common components used in the software and it is used for tracking the list of items. The Java API defines the functionality of the list: sorting the list, identifying items in the list, and adding items to the list. Java API also describes how these actions are performed.

Designing an API

When you are designing an API for multiple business requirements, you must adhere to the best practices which are prominently used in the industry. For API design, you can also incorporate some of the useful features from other popular APIs to ensure high productivity and seamless integration.

Understanding the user requirements and what they need for smooth software interaction is key in developing an efficient application programming interface module. For web-based API, you can use the default standard in the form of JSON. However, if your business requires transactions of large sets of data then JSON might not be the best choice and you can choose an alternative best suited for your requirement.

API development and integration in applications have become pretty common today and thus API developers are in great demand. If you are looking for lucrative API development jobs then you can find the best remote API developer jobs at Turing.

The APIs are one of the most critical components of modern software development and they play a crucial role at different levels of the application stack. These APIs define application functionality by managing abstraction for smooth interaction between the different modules. Highly efficient API modules provide seamless, fluid, and smooth deployment of software systems for maximum scalability.

Integration of APIs for cloud architecture

Cloud computing is one of the modern ways of delivering enterprise solutions and it has been widely adopted by companies globally. A practical cloud application requires communication with the microservices architecture, and well-designed APIs provide this. The microservices architecture uses the application programming interface features for providing smooth interaction between different operating systems and environments. The cloud APIs also enable the enhancement, addition, or modification of services without impacting other services.

Wrapping up

APIs play a critical role in the development of modern software solutions and they continue to evolve with changing requirements of the industry. If you are building custom enterprise-level applications, then having skilled API developers to lead your development projects is hugely significant. You can use deep jobs platforms for sourcing and recruiting the best API developers from around the world, within a span of 3 to 5 days.


  • Author

    Huzefa Chawre

    Huzefa is a technical content writer at Turing. He is a computer science graduate and an Oracle-certified associate in Database Administration. Beyond that, he loves sports and is a big football, cricket, and F1 aficionado.



What's up with Turing? Get the latest news about us here.


Know more about remote work.
Checkout our blog here.


Have any questions?
We'd love to hear from you.

Hire remote developers

Tell us the skills you need and we'll find the best developer for you in days, not weeks.

Hire Developers