Modernization you can check
Keep the logic. Replace the system.
Many rewrites go wrong because the rules in the old code were never written down anywhere else. Rebuilding from memory is where they get lost.
We read the business rules out of your source code into a model, generate the new application from that model rather than retyping it by hand, and test the new system against the old one.
Led from Tokyo or the US.
Further reading: Legacy Modernization Without the Rewrite, PowerBuilder to web, VB6 migration
Which path fits
It depends on what your system runs on today. Deep legacy conversion runs under Vivify, our modernization brand.
Legacy stack: Vivify
Your system runs on PowerBuilder, VB6, COBOL, Oracle Forms, RPG, Classic ASP, WebForms, or a similar platform that is hard to staff and hard to extend. Vivify converts it to standard, modern code you own.
Current stack: Fluxweave
Your app is on a current language and framework but needs new features, better performance, a redesign, or room to scale. We work on it directly.
Extending a modern appHow Vivify converts a legacy system
Most of what your system does is already written in its code. Vivify reads it into a model and generates the new application from that model, instead of translating the old code line by line.
- 1
Analyze
Vivify's Code Analyzer maps the screens, modules, data paths, and dependencies in your source, along with the business rules inside them. Gaps are flagged for an engineer.
Map of screens, data, and rules - 2
Model
What the analysis finds goes into a model of the system's screens, data, and rules. That model becomes the spec for the new application.
A model that serves as the spec - 3
Generate
Vivify's Code Transformer generates the new application from the model by a fixed set of rules, as standard TypeScript and React, or Vue and similar where your standards call for it.
TypeScript and React code - 4
Review
Engineers handle the architecture, the components with no modern equivalent, and the unusual code, then sign off on the test results.
Signed-off test results
How you know it still works
The new system is tested against the old one, not assumed to match it.
Side-by-side testing
The old system and the new one run on the same inputs, and the outputs are compared automatically. Differences show up in the test results.
Tests from your test plans
Vivify builds the automated tests from your existing test plans, or even outlines of them, so they cover the behavior your business depends on. Your team keeps the tests after handover.
A second check from the model
The rules in the model were read from your source code, so the new system can also be checked against them, separately from the tests.
You can also migrate in stages, checking each one before moving on.
A different approach
A hand rewrite rebuilds the rules from memory. A model-driven conversion carries them over from the code, then tests them.
Rules from memory
Manual Rewrite
- Business logic Re-interpreted by developers
- Timeline Long parallel development
- Testing Written from scratch, often incomplete
- Documentation Usually an afterthought
- After launch Back to manual development
Rules from the code
Model-Driven Modernization
- Business logic Read from the source code, including undocumented rules
- Timeline Shorter: most of the code is generated
- Testing Automated side-by-side tests built from your test plans
- Documentation Recovered from the code during analysis
- After launch Standard code your team, or Fluxweave, can build on
What isn't automatic
Most of the code converts automatically. The rest needs judgment, so engineers do it by hand.
Architecture
Old applications assume a desktop talking straight to a database. Deciding how that becomes a browser, an API, and services is a judgment call.
Pieces with no modern equivalent
Some old controls, third-party components, and platform calls have no direct replacement, and long-lived systems have undocumented corners. Engineers handle those by hand.
Where AI fits
The conversion runs on fixed rules, so the same code produces the same result every time. AI helps with the pieces automation can't convert, with building tests, and with unclear old code, and its output goes through the same tests.
When it's not the right fit
Converting the code makes sense when its business logic is worth keeping. It is usually the wrong choice when:
- You want to redesign the business process itself, not just the technology under it.
- Most of the current functionality is no longer used, so rebuilding a small core is faster.
- The function is standard and an off-the-shelf package or SaaS product already fits.
Projects are often a mix: convert the distinctive core, replace the standard parts with a package, and leave unused features behind.
After the conversion
You own standard code with no proprietary runtime underneath it. When the conversion is done, Fluxweave can build on it.
- New Features Add what the old system could never support, including AI features, mobile access, and new workflows.
- UX and Integrations Redesign the screens people use every day and connect the system to the tools around it.
- Ongoing Development When the work keeps going, a dedicated team keeps adding to it. You run it, and the code is yours.
Start small
Prove the approach on your own code first.
Vivify, our modernization brand, starts with a free assessment of your code. A proof of concept on a slice of it then shows your own code converted before you commit.
Book a free assessmentCase studies and more detail on vivifytechnologies.com
How we do it
What every project gets, whether you digitize, launch, or upgrade.
Reusable infrastructure
Sign-in, messaging, data, payments, and real-time, proven in production for more than a decade. We reuse what's solved and spend the effort on what makes your product different.
Design-led thinking
Design comes before code. UX research and wireframes first, so what we build is something people want to use.
Security built in
Access controls, audit trails, and careful data handling from day one, with the discipline of our HIPAA-ready healthcare work on every project.
AI-accelerated delivery
AI handles the repetitive work. Senior engineers check everything it produces, security included.
Senior experience
Since 2014, senior leads in the US and Japan have run every project. They know where software projects go wrong, so you get fewer surprises.
Capacity when you need it
When the work grows, our extended team in Vietnam and specialists in Europe and South America add capacity. Your lead stays the same.
Common questions
Who do we contract with, Fluxweave or Vivify?
Fluxweave. Vivify is our modernization brand. You contract with Fluxweave LLC, or with Fluxweave KK if you are in Japan, and the same team handles the conversion and the new features after it.
Which legacy platforms can be converted?
COBOL, RPG on IBM i, PowerBuilder, VB6, Oracle Forms, Delphi, Classic ASP, .NET WebForms, legacy Java, and more. The new application is generated as standard TypeScript and React, or Vue and similar where your standards call for it.
Is AI rewriting our code?
No. The conversion runs on fixed rules. AI helps only where automation can't convert, and its output is tested against the old system.
Who owns the converted code?
You do. It's standard code with no proprietary runtime underneath, and your team keeps the automated tests after handover.
How do we get started?
With a free assessment. Share your code, and we tell you what converts, what needs engineers, and what the next step costs. For a modern app, the free App Review works the same way.
Get a plan for your legacy system
Tell us about your system and goals. Vivify, our modernization brand, starts with a free assessment of your code.