Securing Legacy SOAP Integrations in a Modern Enterprise Architecture
Contract-first redesign, security requirements definition, authentication approach evaluation and interoperability testing.
Context
A legacy enterprise system providing core data was exposed via a SOAP interface that did not fully meet current security and integration expectations in regulated environments.
Problem
Integration with newer applications was constrained by outdated security mechanisms, unclear contracts, and inconsistent authentication and authorisation handling across consumers.
Constraints
- Existing legacy SOAP infrastructure
- Strict mutual TLS and transport security requirements
- High availability and backward compatibility needs
My role
Responsible for analysing the current integration approach, validating security and authentication options, and supporting the design of a more consistent and secure target integration.
Solution
Defined a security-aligned, contract-first SOAP integration approach and introduced a mediation pattern to standardise authentication, error handling and interoperability between legacy and modern consumers.
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Key decisions
- Evaluated an API gateway / mediation layer for integration standardisation
- Aligned the WS-Security and transport security approach
- Defined a contract-first WSDL structure and validation rules
Outcome
- Improved interoperability between legacy and modern systems
- Clear and documented integration contracts
- Reduced security ambiguity around legacy services
- Increased consistency of authentication and authorisation handling
- Improved maintainability of the integration layer