Legacy Enterprise Platform Refactoring

The platform consisted of approximately 25 interdependent desktop applications developed over time by different teams. System boundaries were unclear, and responsibilities were distributed across components without consistent interfaces.

Parts of the system were implemented in Delphi, which introduced a dependency on legacy technology with limited internal support. Maintaining and evolving these components became increasingly difficult and constrained further development.

Core business logic was tightly coupled with data access and UI layers. The system relied on multiple databases, including Oracle and MS SQL, with partially overlapping schemas and synchronization mechanisms.

Documentation covered only part of the system, and several key domain experts were no longer available. Understanding data flows, dependencies, and edge cases required direct analysis of the codebase and production behavior.

Performance and reliability issues affected daily operations. Data synchronization between field applications and central systems was slow and error-prone, and accumulated defects made updates risky.

The platform had to remain available throughout the refactoring effort, with more than 10,000 daily users relying on it to enter, synchronize, and report field data. Changes had to be introduced without interrupting active operations or compromising data consistency.

• Mapped the legacy application landscape across approximately 25 interdependent desktop applications, database components, and synchronization workflows.
• Recovered business logic from code and runtime behavior where documentation was incomplete and original domain experts were no longer available.
• Stabilized high-priority production defects affecting field operations, reporting workflows, and data synchronization between local and central systems.
• Moved selected Delphi functionality into web-facing layers by isolating business rules, validating behavior against live workflows, and reducing dependency on legacy desktop components.
• Removed schema owner dependencies to reduce database coupling and improve portability across customer-specific environments.
• Optimized field-to-central synchronization by improving database access patterns, execution flow, and error handling in daily data exchange workflows.
• Separated monolithic responsibilities into service boundaries with clearer contracts between application, database, and integration layers.
• Improved data integrity controls across Oracle and MS SQL environments to reduce inconsistent records during synchronization.
• Introduced automated regression testing for critical workflows to make production refactoring safer and reduce update risk.
• Set up structured delivery routines including onsite knowledge transfer, sprint planning, milestone tracking, and communication practices for a distributed team.