Tips on creating robust APIs as a back end developer

Application Programming Interfaces or APIs create software to interact with an existing application. Creating APIs is an integral part of a back end developer’s job. Still, frontend developers too can use APIs to make web applications more dynamic by adding features such as newsfeeds and image galleries. Most production-ready applications fail to find large-scale adoption because of API issues such as poor design, unresolved bugs, and lack of documentation.

As a back end developer, you must create APIs that are clear, well-documented, bug-free, and easy to use. Follow the guidance in this post to develop robust APIs that find broad adoption.

Uniform Interface Principle

APIs that follow a uniform interface are the easiest to work with. A robust API has the same format for ‘requests to’ and ‘responses from’ messages in the same language and uses the same protocol. Some widely used APIs utilize HTTP protocol that allows HTTP requests such as GET, POST, PUT, and DELETE.

Optimize with Caching, Sorting & Pagination

Application databases grow with time. As APIs’ only function is to retrieve data, you must make arrangements to optimize the process as the data grows. It is essential to ensure speedy retrieval of data. This is possible through caching, sorting, and pagination.

Caching is essential to maintain system speed. You must include a cache strategy to allow faster information retrieval when building APIs. You can use API development tools like Redis and Memcached for this purpose. Including caching rules in the API saves costs for both server and client. The server can keep a cache file to avoid fetching the same information multiple times. You can also include rules in API to determine whether resources can be cached by the client and for how long.

Sorting is a limitation put on the API to ensure that data is received by the client one by one as per the requirement, modification, or preset conditions. Pagination determines how much information is displayed in a single request and at what frequency.

Optimization is vital to ensure APIs have good response time and minimum processing time.

Take security seriously

Whether the Facebook’s 2018 data breach or JustDial’s database leak fiasco in 2019, some of the enormous data and privacy lapses are due to a lack of API security. A few things damage an API’s reputation as severely as a security breach.

APIs are high-stake endeavors for companies, and thus, you must incorporate authentication, authorization, and encryption in API development.

Authentication

Authentication is necessary to validate a client’s connection to the API. You must make authentication stateless for maximum security, enforcing each API call to be authenticated individually, even if the client connected successfully before.

Keep in mind that the best APIs are the ones that keep the authentication process more straightforward and do not impede developers while protecting data.

Authorization

After successful authentication, you need to set authorization to determine what the client can do or what information you can access. Well-designed APIs follow the principle of least privilege. According to this principle, a client must have a minimum level of access to perform the required function.

Encryption

There is no scope for unencrypted data today. All API connections must encrypt the client-server data, especially if the API allows connection over public WIFI.

Error validation must be useful

It will be rare that your API never runs into a problem as several things can go wrong. The client might mess up the request format, the authentication, or request a resource that no longer exists.

To curb some of the frustration in the face of unexpected errors, you must include additional information about the error. Your API should return the appropriate HTTP response status code and the message as to why the error occurred.

HATEOAS

When a client requests data from a REST API, it gets the details of the resources back, nothing more. It’s like viewing a web page but not being able to perform actions on it.

HATEOAS (Hypermedia as the Engine of Application State) is a module of the REST application architecture that allows API responses to include the operations on the resources. It makes it possible to transform REST API static calls into dynamic calls to perform actions.

Validation and Testing

Validation is important to ensure the correctness of the data that API calls return. Generally, APIs use client-side validation for prompt feedback. But as a back end developer, you must learn about the principles of server-side validation.

It is vital to test APIs to evaluate their reliability, security, performance, and functionality. You can use some popular API development tools like Postman, JMeter, and SoapUI for API integration testing.

Bottomline

In back end development, API building is an important concept. If you are a back end developer, follow these design practices to create great APIs, not those that compromise the entire system’s integrity.

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