Companies leveraging IBM i to run their core systems of record often require integrating these applications with external CRM, eCommerce, and other enterprise applications. Modern integration architectures focus on surfacing the data and business logic via reusable and standards-based APIs or event streams.  

There are several approaches and tools available to implement APIs for IBM i based applications. One option is to implement and host the APIs directly within IBM i application platform. IBM Integrated Web Services (IWS), Krengeltech’s RPG-XML, Profound API, and several other tools fall into this category and offer products to develop and operate the integration assets within IBM i environment. This option offers several benefits, the most obvious being the simplified architecture and no need for a separate dedicated middleware layer. As with everything in life, it comes with a number of downsides and considerations. As companies evolve and mature their architecture and integration competence, these points become more prominent. Most customers eventually shift most of their integration workloads to dedicated integration platforms such as Mulesoft Anypoint, Confluent Cloud, or AWS or Azure integration stacks that offer high performance, advanced security policies, governance, and process automation out of the box.