Case Study

Visayan Global Insurance Group, Inc.
25th Floor, Karakoa Tower
789 North East Moonson Avenue, Balangay District
Cebu City, 6000

Refactoring and Documentation of Legacy Code Instead of Upgrading to React/Django

To: Ma. Christina De Leon – Head of Process Optimization
From: Airo B. Tacujan – Operations Assistance and System Analyst
Date: December 26, 2025
Subject: Refactoring, Comprehensive Documentation, and Archiving of Legacy Systems (10-Year Span) Using Updated JS/PHP, in Lieu of IT Department’s React/Django Upgrade Proposal.


I. Executive Summary

Our core operational system is 15 years old. While the IT department has proposed a full rebuild using a modern React/Django stack, a complete rewrite at this stage introduces significant operational, regulatory, and financial risk.


II. Why a Full Rewrite Is High Risk Right Now

The current system is not just software—it is the accumulated result of 15 years of production issues, regulatory exceptions, and operational fixes.

Key risks of a full rewrite:

  • Loss of critical business logic
    Many low-frequency processes (billing edge cases, regulatory reporting paths) are poorly documented but essential. These are precisely the elements most likely to be missed in a rewrite.
  • Operational disruption
    Reimplementing the system requires rediscovering and validating years of historical decisions. This creates a high likelihood of regressions affecting Billing, Claims, and Compliance.
  • Regulatory exposure
    Even brief inconsistencies during migration could trigger compliance findings, penalties, or audit failures.
  • High upfront cost with delayed value
    A rewrite demands significant investment before delivering stable, measurable improvements.

III. Current State: Manageable but Fragile

Over the past two years, we recorded 43 incidents, primarily driven by:

  • Tight coupling between modules
  • Undocumented dependencies
  • Manual operational workarounds

Despite these issues, the system:

  • Remains functional
  • Has known behaviors
  • Has already passed years of regulatory scrutiny

This makes it fragile but predictable, which is preferable to a brand-new system with unknown failure modes.


Recommended Strategy: Stabilize First, Modernize Later

Phase 1: Risk Reduction (Immediate)

  • Incrementally refactor the most incident-prone modules
  • Document workflows, dependencies, and regulatory exceptions
  • Archive historical fixes to preserve institutional knowledge
  • Optimize performance bottlenecks affecting operations

Phase 2: Controlled Improvement

  • Reduce incident frequency and MTTR
  • Eliminate manual rework where safely possible
  • Introduce testing around critical execution paths

Phase 3: Re-evaluate Modernization

  • Conduct annual reviews
  • Reassess platform migration once high-risk areas are stabilized and well-documented
  • Maintain a future modernization roadmap without committing prematurely

Why This Is the Safer Business Decision

ConsiderationIncremental RefactoringFull Rewrite
Operational RiskLowHigh
Regulatory ExposureLow (known behaviors)Medium–High
Cost ProfileGradual, controlledLarge upfront
Time to StabilityImmediate improvementsLong ramp-up
Failure ImpactLocalizedSystem-wide

Final Recommendation

Stability before transformation.
A modern platform may be appropriate in the future—but only after we reduce unknowns, document critical logic, and protect the business from avoidable risk.

This approach keeps operations running, protects compliance, and gives leadership flexibility instead of locking the company into a high-risk, high-cost rewrite.