API Facade for Incremental Customer Data Management System Modernization

About the Client

The client is a mid-sized national bank. The client’s customer data management system had an aging architecture with tightly coupled elements. With an extensive network of disconnected data sources and a complicated web of many interconnections, the system struggled to streamline business processes. By facing an increasing flow of requests, the bank introduced updates and modifications that eventually led to downtime and business disruptions. 

Goal

The client needed to overcome its most pressing bottlenecks and partnered with our company, which had experience in migrating legacy software:

• Develop an API facade to consolidate data flow from modern banking apps and services without coupling to the specifics of the legacy system’s complex nature. 
• Use an API-led approach to incrementally improve real-time data extraction and processing instead of immediately overhauling the existing back-end system.
• Iterate back-end modernization while the old system is running and eventually get to a point where legacy components are retired.

Work Description

1. Cooperation with stakeholders.
   1. We worked with the project’s stakeholders to communicate the benefits of the chosen development approach: a risk-free transition and minimal disruption to the legacy system.
   2. The team identified business goals and needs to align on the most critical aspects of the project. It was necessary to ensure the system underwent gradual modernization and became flexible and accessible.
2. Audit of the legacy system.
   1. The audit revealed the key functionalities, integration points, and data flows that needed to be exposed via APIs.
   2. Our specialists prioritized high-value areas for the early stages of API development: customer profile management, transaction history access, and real-time data synchronization.
3. API facade design.
   1. The team implemented an API layer to let the traffic flow to a legacy system through a unified interface.
   2. We ensured the design was modular, scalable, and secure and had room for subsequent improvements by gradually replacing back-end components.
   3. As the client dealt with sensitive data and adhered to strict regulations, we focused on incorporating robust data governance and compliance measures within the API layer.
4. Iterative API development.
   1. The team deployed prioritized functionalities in short development cycles, starting with retrieving customer account details and transaction history.
   2. We connected the most critical endpoints requiring real-time access to customer data to the API facade. Our developers integrated mobile banking apps and online customer service portals to reach the objectives of this stage.
5. Encapsulation of the legacy system.
   1. Our developers separated the legacy system’s underlying logic within the facade. This approach helped shield the rest of the system and simplify API usage.
   2. The team implemented backward compatibility to preserve concurrent legacy and new software operations.
6. Integration with external systems.
   1. We set up APIs to facilitate uninterrupted data exchange with modern banking services, third-party payment gateways, and cloud-based customer engagement tools.
   2. The team introduced new front-end features, including real-time account notifications and self-service profile updates. They pulled data from the API facade instead of the legacy back-end.
7. Testing and validation.
   1. Our developers and QA specialists conducted scalability, performance, and security tests to validate the system’s capabilities.
   2. Integration testing was also crucial for verifying that new customer-facing applications interacting with the APIs functioned as expected and delivered a seamless UX.
8. Monitoring and optimization.
   1. The team configured system monitoring and alerting to observe current performance metrics and detect issues as they happen.
   2. We incorporated user feedback to refine the API design and adjusted its architecture to accommodate future scalability needs.
9. Gradual back-end phase-out.
   1. Once the developers stabilized the API facade, they replaced the legacy system’s components incrementally without affecting the interface used by external systems or users.
   2. Each change in the back-end was isolated, leading to an uninterrupted transition to a modern environment.
10. Long-term support and evolution.
    1. The team continued enhancing the API facade to support new business needs and integrations, including mobile banking and external financial services.
    2. The legacy system was successfully retired by modernizing each back-end component. The developers maintained the API layer to ensure ultimate flexibility.

Results

• 30% faster delivery of customer-centric services through streamlined integrations with mobile banking features and real-time account notifications.
• 40% lower downtime instances during the transition due to the separation of the API layer from the legacy back-end.
• Improved scalability and performance, allowing the bank to accommodate higher transaction volumes and provide real-time data access to multiple endpoints.
• Seamless path to complete back-end modernization, with new components being replaced incrementally behind the API facade instead of a complete system overhaul.