Legacy Modernization covers strategies for replacing and modernizing legacy systems: Delphi, VB6, Access, monolithic applications and outdated infrastructure.
Old systems create risk on three fronts: rising maintenance cost, shrinking know-how for old technologies and growing security gaps. Technical debt then slows down every new feature request.
We compare three modernization approaches so you can choose the right path:
- Incremental migration: replace the system module by module while the old one stays live.
- Strangler Fig: wrap a new layer around the legacy core and retire it step by step.
- Greenfield rewrite: start from scratch when the old codebase can no longer be saved.
Our articles detail risk assessment frameworks, cost-benefit analyses and phased rollout plans. The goal stays the same: minimize disruption to daily operations.
We also discuss how to preserve business logic embedded in decades-old codebases. Modern tooling and cloud infrastructure follow later, once that logic is written down and covered by tests.
Data migration needs the same care, because automated validation prevents silent data loss.
See also Delphi Development and Software Rescue for technology-specific guidance. Our Software Development category covers the engineering fundamentals that underpin every modernization effort.
Use these guides when you first explore Legacymodernization or need to check a plan. The advice draws on software project experience since 2010.
Browse the category overview for related decisions. For a project-specific question, send the context through our software project contact page.