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What is an API and how does it enable Connectivity?

API (Application Programming Interface) is a programming-based software interface that acts like a bridge between two or more applications and/or systems, enabling them to seamlessly communicate with each other without making any change in the original application or system.  

A real-life example to understand API application better

  • Booking tickets for a concert or sports event on a tickets marketplace like Seetickets and Ticketweb, is a perfect example of API connectivity. Whether online or with a mobile app, information on the different events, dates and times, locations, prices and seats availability, is readily available and updated in real time - a seamless user experience with a complex process in the background.

These marketplaces operate as aggregators; connecting to the different entertainment companies and displaying the information on their own applications and user interfaces. These connections are being achieved through APIs that these entertainment companies have exposed for marketplaces to connect and get the necessary information, all in real time.

Why should businesses opt for API-led integration over traditional methods?

  1. Re-usability: The logic for most of the APIs is built using a service oriented approach, which means a single API can be re-used across different applications by implementing only little tweaks based on the project at hand. This prevents duplication of effort and increases the productivity of developers by allowing integration to be addressed in small pieces.

  2. Loose Coupling: Implementing changes to even a single component of a legacy system integrated via traditional integration methods, like point-to-point, can have a system-wide impact, with unexpected and undesirable effects. API-led connectivity brings in loosely coupled architecture where components can be added, replaced or modified without any changes in the operation of other components. Separate API tiers allow for a different level of governance and control at each layer.

  3. Scalability: For a business, scalability refers to the change in number of customers or users, which in turn affects the workload that needs to be processed and overall capacity needs. APIs are the best mode of integration to make this scalability feasible. Just a few lines of code for an API makes it possible to connect any new system with the existing infrastructure without making any change in the original hardware or software. APIs enhance the architecture of the servers to handle more transactions per second.

  4. Security: The General Data Protection Regulation (GDPR) is a recent law implemented within the European Union to protect the data of its citizens. API-led connectivity will enable companies in determining who can request data from their systems, how such requests will be answered, and how to protect the confidentiality of those answers with security measures such as encryption.
What is an API

The 3 Types of APIs that drive API-led Connectivity

In the MuleSoft integration space, preparing an API-led integration architecture is divided into 3 layers. The topmost layer is called the Experience Layer which enables users to interact with an IT ecosystem of a business. The bottom most layer is called the System Layer, which houses the core systems in an IT ecosystem. And the middle layer is called the Process Layer, which pulls data from bottom layer, applies business logic to process the data and pushes the data in any desired format asked by the top layer. Each layer functions by its own set of APIs as mentioned below.

  1. Experience APIs: Experience APIs are utilised for Mobile Apps and Web Apps. These are used to avoid setting up separate point-to-point integrations for each channel and instead create a common data source, where data can be reconfigured based on the source which is looking to access it, without making any change in the original database servers. In simple terms, it enables displaying the same data into multiple formats based on who is asking for it.

  2. System APIs: Legacy systems, SaaS apps, mainframes, FTP servers are some of the core underlying systems of any IT architecture. System APIs hide the complexity of an IT infrastructure from the users. These type of APIs are the ones enabling loose-coupling by providing a platform to access systems of record, and exposing data into each record in a canonical format. This avoids any need of interfering with an already complex IT ecosystem present in the business.

  3. Process APIs: Process APIs are implemented when a business is looking to scale up the current IT infrastructure, either in terms of onboarding new systems as a result of expansion into new geographies or integrating different legacy systems of an already existing vast IT ecosystem. Process APIs enable  developers to create independent data source points as well as independent target channels to deliver the data. In simple terms, Process APIs feed in the data coming from System Layer, without any need of interfering with the legacy systems; apply business logic to them and transform them as required and orchestrate the data as demanded by the Experience layer, thus in turn satisfying the needs of each user both geographically and demographically.

If you would like to find out more about how Systems Integration could help you make the most out of your current infrastructure while enabling you to open your digital horizons, do give us a call at +44 (0)203 475 7980 or email us at

Other useful links:

Integration trends that will drive 2018

Api recipes

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