Service
Legacy Migration
We modernize aging, heavily customized systems without disrupting operations, migrating to modern architectures one step at a time so the business keeps running.
What we build.
Six disciplines, from first architecture to production support.
Application re-architecture
Monoliths restructured into modern architectures without starting over.
- Monolith to microservices
- Desktop to web
- Framework upgrades
- Strangler-fig migrations
Cloud migration
On-premise workloads to Azure, AWS, or GCP with zero-downtime cutover.
- Lift-and-shift
- Cloud-native re-platforming
- Hybrid architectures
- Containerization
Database modernization
Legacy databases migrated and tuned on modern, scalable platforms.
- Oracle and Access to SQL
- Cloud database migration
- Schema optimization
- Data validation
API-first transformation
Legacy systems wrapped in modern APIs so they fit today's architecture.
- REST layers over legacy
- Event-driven integration
- Gateway and security
- Gradual replacement
ERP migration
NAV, AX, GP, Sage, and QuickBooks moved to D365 or NetSuite.
- NAV and GP to Business Central
- Sage and QuickBooks to D365
- Custom ERP replacement
- Historical data preserved
Incremental migration
Phased approaches that deliver value at every stage.
- Phased roadmaps
- Parallel run strategies
- Risk mitigation
- Rollback planning
Why Aedista
Why Aedista for modernization
Our stack
Modern tools we build with
.NET Core
Enterprise web and service backends
Java
Large-scale enterprise systems
Node.js
APIs and real-time services
PHP
High-volume web platforms
React
Modern web front ends
Angular
Enterprise front ends
Next.js
Server-rendered React apps
Swift
Native iOS apps
Kotlin
Native Android apps
Azure
Cloud infrastructure and DevOps
AWS
Cloud infrastructure at scale
Docker
Containerized deployment
Engagement models
Three ways to work with us
Fixed cost
A defined scope, priced upfront, and paid by milestone. Best when requirements are clear and stable.
Time and materials
Built for evolving scope. You pay for delivered work, and priorities can shift as you learn.
Dedicated team
Our engineers work as an extension of your team, on your priorities, at your cadence.
Aedista didn't just advise, they built the system alongside us. They understood our operations, made the complex parts simple, and delivered something our teams actually use every day. The result was immediate and, more importantly, built to last.
Trusted by global brands
Frequently asked questions
What is legacy system modernization?
Legacy system modernization is the process of updating aging software, databases, and infrastructure to modern architectures and platforms while preserving the business logic and institutional knowledge embedded in the original system. It can mean re-architecting a monolithic application into microservices, migrating an on-premise system to the cloud, upgrading a database engine, or wrapping legacy functionality in modern APIs. Aedista approaches modernization as a structured process (assess, plan, migrate, optimize) rather than a risky full rewrite.
What is the strangler fig pattern and why does it matter?
The strangler fig pattern is a modernization approach where a new system is built incrementally alongside the legacy system, gradually taking over functionality piece by piece until the old system can be safely retired. Named after the strangler fig vine that grows around a host tree, this pattern lets you replace a legacy application without a risky big-bang rewrite or extended downtime. Aedista has used this approach on platforms including a 25-year medical education system, migrating page by page and module by module while the proven legacy core kept serving production.
How long does a legacy modernization project take?
Timelines vary significantly based on system complexity and approach. A focused database migration or API wrapper project can take 2 to 4 months. A phased application re-architecture using the strangler fig pattern typically spans 6 to 18 months, with new functionality shipping incrementally throughout rather than all at once at the end. Full ERP migrations from legacy platforms typically take 3 to 12 months depending on customization complexity. Aedista structures every modernization as a phased roadmap so your business sees value at each milestone, not just at a single cutover date.
How do you minimize risk during a legacy modernization?
Risk mitigation is built into every phase of our methodology. We start with a thorough assessment to map dependencies and technical debt before any code changes. We use phased migration roadmaps so failures are contained to a single module rather than the whole system. Parallel-run periods let both old and new systems operate simultaneously so your team can validate behavior before cutover. We maintain detailed rollback plans at every stage. And for application re-architecture, the strangler fig pattern means the proven legacy system keeps running in production while new functionality is built and tested alongside it.
Is it cheaper to modernize incrementally or do a full rewrite?
Incremental modernization is almost always lower-risk and often lower-cost than a full rewrite. A full rewrite requires freezing feature development on the legacy system, carries a higher risk of scope creep and budget overrun, and creates a high-stakes cutover where any gap in feature parity disrupts the business. Incremental modernization using the strangler fig pattern or phased migration lets you ship value continuously, keep the legacy system as a safety net during transition, and adjust the roadmap as you learn. We typically only recommend a full rewrite when the legacy codebase is so brittle or undocumented that incremental change is not feasible.
What legacy systems and technologies have you modernized?
Aedista has modernized systems built on virtually every generation of enterprise technology, from classic ASP and VB6 desktop applications to early-2000s .NET Framework systems, legacy ERP platforms including Dynamics NAV, Dynamics GP, and Dynamics AX, on-premise SQL Server and Oracle databases, and monolithic web applications built before microservices architecture existed. Recent examples include migrating a 25-year medical education platform's .NET Framework WebForms backend to a modern NestJS stack, and an 80+ server cloud migration with Dockerization and CI/CD for a SaaS platform serving customers for over a decade.
