Aleksandar Milosevic, Chief Software Architect at banking software provider Asseco SEE explains the business benefits of working with BIAN to define standardised APIs.

Using standard interfaces to consolidate and modernise portfolio

As a vendor that grew through acquisitions, we inherited a rich collection of applications that have their application specific interfaces. Applications that had similar scope ended up having their specific interfaces for essentially the same responsibilities. One of our strategic goals was to cut integration time and cost and over time achieve plug-and-play interoperability between different applications in our portfolio. Another goal was to hide any application or platform specifics behind the interfaces so we can gradually modernise individual applications without disturbing the others. Last but not least, our goal was to enable easier consumption of our interfaces from customers and partners. As we were already using BIAN as a map for application portfolio tracking and optimisation we decided to go a step further with BIAN – to define standard A2A interfaces aligned with BIAN and retire legacy application specific interfaces.

Asseco Reference REST APIs

We formed working groups from domain experts and gave them the charter to standardise REST APIs for Asseco SEE banking applications. One of the biggest challenges when defining a large set of consistent APIs is the alignment of their responsibilities and boundaries. Through our experience with BIAN we learned that we could utilise the landscape for functional decomposition of APIs in which each service domain becomes a candidate boundary for an API definition. Having clear rules for establishing service domains reduced the risk of unclear boundaries and increased the productivity of our working groups.

30 APIs and counting

Since the beginning of 2016, our working groups were able to define 30 APIs and our many product teams implemented those APIs as both consumers and providers. Working on standard APIs had an integral impact on our development organisation and helped broaden the perspectives outside organisational and application siloes. With three banks already using REST APIs and many more in the pipeline, APIs and their alignment with BIAN is a hot topic in almost any discussion that we have with banks today.