TransUnion Migrates Tandem COBOL Credit Processing to Java
TransUnion replatformed its credit reference and credit report processing systems from Tandem COBOL to Java.
The goal was to retire the legacy stack, cut run costs, and improve integration with modern platforms.
Project Overview
As the Tandem systems reached end of life, TransUnion chose to move to Java rather than port and upgrade.
The program portfolio included 200+ applications, split roughly half online and half batch.
We could not have completed this project without it. We have had zero production system outages caused by the new system and there have been no defects found. This was a huge effort and successful because of SoftwareMining.
Approach and Timeline
Automated translation of COBOL modules to Java, with targeted refactoring for readability and supportability.
Early stabilization: the first two months of conversion resolved the majority of compile and build issues.
Phased validation: online and batch flows verified against existing outputs and operational SLAs.
There were far less compilation errors than we planned for and the initial two months of COBOL to Java conversion shook out many issues. Very few occurred after that phase.
Results
Zero production outages caused by the new Java system since go live.
No post go live defects reported in translated components.
Faster integration with internal platforms via standard Java interfaces and tooling.
Business Benefits
Lower total cost: commodity hardware and simplified licensing.
Access to larger in-country talent pools for ongoing support and change.
Improved interoperability with enterprise services, APIs, and CI/CD pipelines.
As the technical lead summarized, the migration reduced costs and increased maintainability while meeting strict reliability targets.