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CASE STUDY / SECURITY / SOA

Cardholder Data Isolation Interface

A standalone Windows application designed to isolate sensitive PAN search workflows from a legacy processor through a service-oriented integration approach.

C#WinFormsWCFSOAC4 Model

Project context

The legacy card-processing environment included workflows for searching cardholder data. The initiative introduced a separate application boundary for the relevant search workflow rather than keeping it embedded in the legacy application.

My role & contributions

  • Built a standalone C# Windows Forms application from scratch for the isolated search workflow.
  • Used WCF and a service-oriented approach to connect the standalone application with required system functionality.
  • Documented the legacy processor and standalone application using C4 Model diagrams to explain components, dependencies, and system boundaries.
  • Helped decouple the cardholder-data search workflow from the legacy processor, supporting a reduction in PCI-DSS audit scope.

Outcome and learning

The standalone interface separated the targeted workflow from the legacy application and provided clearer system boundaries for the associated compliance effort.

Scope note: This public summary omits client identity, real system diagrams, endpoint details, cardholder data, network boundaries, credentials, and implementation specifics that could expose a production environment.