In this day and age, people care a lot about the experience of using websites and mobile apps. As a result, developers are always trying to improve the user experience. This effort demands the development of responsive and fast applications. Issues with servers mostly cause poor user experience. As such, web service APIs (Application Programming Interface) are essential aspects of web and mobile development, which tries to optimize the performance of applications.
Interoperability
Most mobile software developers create updates for their applications periodically. These updates are made to improve the app's performance by optimization and resolution of errors. However, many mobile users do not care to update the application on their devices. A handful of individuals may take years to install new updates. After some time, older versions of an app become obsolete, which eventually becomes a problem. In such cases, these older apps may likely require outdated Application Programming Interface contracts. This type of problem necessitates the need for backward compatibility for programming interfaces that are used by mobile applications.
Two methods can be used to achieve backward compatibility. These methods are:
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Expand-Contract Pattern;
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Versioning.
Expand-Contract Pattern
This approach is also called Parallel Change. It is used to prevent compatibility changes with API changes. This method can be understood by taking a look at changing the name of a field. When the name of a mandatory field is transformed from a payload for an Application Programming Interface reaction, this process constitutes a change of backward-incompatible (breaking) API contract. The best way of dealing with this problem is to add another field. The actual field can be kept unless it becomes disposable.
Versioning
Another approach is the use of API versioning. This allows you to keep and use old and new Application Programming Interface versions simultaneously. After a long time, the older version can be let go. Many developers are encouraging users to update applications by pushing updates within these apps. This practice encourages users to update their applications.
Mobile-Friendly API Contracts
When developers use the twelve-factor app methodology, they should push to do the following.
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Prevent or limit continuous fetching to limit data retrieval.
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Prevent under-fetching. In such a situation, an API response is unable to retrieve the required data for an app. As such, several API requests occur. The optimal operation requires only one action.
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Limit JSON Verbose Format over XML.
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When an Application Programming Interface cannot perform as mentioned above, it will consume the bandwidth and battery of a user's device. Ultimately, it will affect the overall user experience. Luckily, the mobile APIS can be optimized using the following techniques.
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GraphQL helps to optimize fetching by keeping it at an acceptable level.
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A Pragmatic RESTful API can be used and optimized for each use case.
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Pagination can help limit the response of an API.
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The use of compressed API responses can be helpful for large APIs.
There are many challenges associated with the backend, which is general-purpose to handle optimized Application Programming Interface contracts for apps. Dedicated optimized backends can be achieved by using BFF (Backend For Frontend).