When your customers demand more utility from your current system than it was originally designed to provide due to Legacy limitations and constraints, what are some of the options you have for giving your customers a satisfying outcome? A complete rewrite to modernize a complex financial application with millions of lines of legacy code is not an easy task. I have seen it attempted. And, I have seen it both succeed and fail. In my view, the best approach is to carefully choose and replace parts of the legacy system, reusing the main core of the application. Consider replacing the following components as a way to increase your system’s value and to modernize your application: a Business Rules Engine (BRE), a well-defined list of REST APIs, and a modern Business Process Management (BPM) workflow that provides a work allocation / distribution engine.
Business rules are key to your customer’s success. For most legacy applications, these rules are embedded within the code making it very difficult to change. But adding a parallel structure to externalize these business rules can provide a huge benefit to your customers. You would then be able to run the rules alongside your existing legacy rules. This approach will provide the capability to build new rules and logic in the externalized rules engine. A business rules engine (BRE) is a software component that allows non-programmers to add or change business logic. This approach eliminates a lot of risk since your existing legacy rules remain intact and can be replaced once your customer has signed off on the new rule engine. This will give your customer the capability to change their business rules without the need for programming.
APIs hold the key to legacy modernization and, in turn, solving the legacy system challenges. APIs act as the main door for legacy applications to access the data, business logic, or functionality. Adding a good API Gateway to protect the integrity of the legacy system
enables a secure and governed access to the underlying data without impacting the core legacy logic. This allows organizations with older systems to adapt to modern business needs and, more importantly, quickly adopt new technologies and platforms.
BPM allows you to leverage legacy functionality with modern applications that combine business logic and your customer’s business process data. BPM improves collaboration between your business and IT by abstracting the business process from the underlying code, and allowing loose coupling with the legacy code. BPM can help you identify the human interface requirements and automate work allocation handling through intelligent routing and tracking of human task assignment.
In leveraging these three simple technologies – BRE, APIs and BPM –you can easily wrap your legacy code with the modern architecture needed to meet all the changing business requirements of your customer.
About the Author:
Vinay Bhatia is an experienced product leader, passionate about building financial products that delight customers. He has an extensive background in technology, cloud and agile software development.