Legacy Modernization for Enterprise
CoreLine modernizes enterprise legacy systems that have outgrown their architecture. Monolith decomposition, mainframe migration, database re-platforming, and cloud-native re-architecture - delivered incrementally with zero-downtime cutover and full data integrity.
Assessment & Roadmap
Legacy codebase audit
Dependency and risk mapping
Phased migration roadmap
Re-architecture & Migration
Monolith to microservices
Mainframe to cloud-native
Database re-platforming
Cutover & Continuity
Zero-downtime migration
Parallel validation testing
Team knowledge transfer
Sound familiar?
Your engineering team spends 70% of their time maintaining legacy systems instead of building features customers are asking for
The developer who built the core system left three years ago and no one fully understands how the billing module works
Every vendor pitches a full rewrite, but you can't afford 18 months of parallel running and you can't risk downtime
Your legacy platform can't handle the traffic or data volume you're scaling into, and patching it is getting more expensive each quarter
Enterprise modernization is surgery, not demolition. We assess what works, replace what blocks you, and migrate incrementally so revenue-generating systems never go offline.
We map the existing architecture: data flows, integration points, undocumented business rules, and technical debt hotspots. The output is a phased migration roadmap with risk scores and ROI projections for each phase.
New services wrap and replace legacy components one at a time. Each migration step runs in parallel with the legacy system, validated against production data before traffic shifts. Every step is reversible.
Production cutover with zero downtime. We run parallel validation, regression testing, and performance benchmarking before decommissioning legacy components. Full runbook and knowledge transfer to your team.
Modernization outcomes
Using solutions such as React Native, Flutter, AWS, and many others makes it possible for us to upgrade your product as much as possible and to achieve a thriving collaboration. Here you will find our guide through our most used technologies and case studies related to each one.
AWS offers the tools to build powerful, flexible, and scalable applications, from compute and storage to databases and content delivery.
Simply put, Flutter is Google’s cross-platform framework that lets you build mobile, web, desktop, and embedded apps, all from a single codebase.
React Native is Facebook’s cross-platform framework that combines the best of React with native platform features - perfect for new projects or enhancing existing ones.
Other technologies we use
Frequently asked questions
Almost never. Full rewrites are the most expensive and highest-risk approach. We assess each component independently: some can be wrapped and left in place, some need refactoring, and only the ones that actively block your goals get replaced. The migration roadmap shows exactly what changes, what stays, and why.
We use the strangler-fig pattern: new services run alongside legacy ones with traffic shifting incrementally. Database migrations use dual-write or CDC (change data capture) patterns so both systems stay consistent during transition. Every step is reversible until you're confident in the new system.
PHP, .NET Framework, Ruby on Rails, Java/Spring, COBOL mainframes, and custom monoliths. We migrate to TypeScript/React, Node.js, Python, Go, and AWS/GCP infrastructure. Database migrations from Oracle, SQL Server, MySQL, and flat-file systems to PostgreSQL.
First production milestone in 8-12 weeks. Full enterprise platform modernization runs 6-18 months depending on system complexity, integration count, and regulatory requirements. We publish a phased roadmap at discovery with clear milestones - you see production improvements before the full migration completes.
Data integrity is non-negotiable. We run parallel databases during migration, validate consistency at every step with automated comparison tools, and maintain rollback capability until cutover is fully validated. Historical data, audit trails, and reporting continuity are preserved throughout.
