The Yonder Modernization Framework

The tempting shortcut

Many business leaders I spoke to this year have had the same thought: if AI writes code this fast, why not point it at our legacy product and let it rebuild the whole thing? It is a fair question, and the shortcut is real. At our AI Executive Briefing in Windsor, our CTO Remus Pereni showed how an AI agent rewrote AWS CardDemo, a 27,000-line COBOL application, in four days. Another run did it in seven days for an estimated $231.

So why would you need a modernization framework at all? Well, because speed was never the hard part.

 

What a do-it-yourself rewrite doesn’t do

The value of critical software is not its code. It is the business rules within the software itself: laws and regulations, industry standards, and the custom processes your customers have built their operations around. Even one of the smallest healthcare solutions we work on includes 100 forms, 190 functionalities, and 1,800 business rules, many of which exist only in the source code or in someone’s head.

So we investigated and measured unguided AI rewrites against the legacy original; 22% to 30% of the functionality had changed in the unguided rewrites, including missing rules, invented rules, and altered flows. That would mean that, for a small pension solution of 800,000 lines and 275+ functionalities, at least 60 to 83 functionalities would behave differently. You just don’t know which ones until a customer finds out.

The reasons are structural. Agents fall back on crude text-matching tools and cannot judge what they do not see. As Remus put it: skills without evals is gambling. And gambling means losing your clients’ trust you have built over the years.

 

YMF removes the gamble

The Yonder AI Modernization Framework (YMF) maintains AI speed and removes the gamble. It brings three layers together in one approach: the machinery; our AI-DLC method, where agents build, and people decide; and the Yonder Modernization Process, shaped over 30+ years and 65+ large-scale modernizations.

YMF follows a clear and well-thought-out path:

• Scan reads every screen, rule, and data flow from the source code, using deterministic tooling and evaluated skills
• Model designs the future based on that evidence, so you decide what to keep, change, or leave behind
• Build lets long-running agents handle the migration while people govern architecture and quality
• Decorate adds AI features, mobile access, or self-service portals where they bring value
• Validate and Maintain close the loop with independent testing, sign-off by your own people, and a knowledge handover to your teams

 

 

Currently, we have built and used YMF for VB6 modernizations, and the framework for Delphi is ready in the near future, with other languages following, such as C# and .NET. For our current stack, YMF achieves 3 to 9 times higher velocity across the entire process.

Vibe modernization promises up to 100 times. Governed modernization delivers a gain you can actually count on, trust and use as a solid foundation for your future.

 

What it means for your business

For a business owner, the difference is not technical

• It is lower risk, because an evidence-backed path replaces the leap of faith of a big-bang rebuild
• It is a predictable cost because scope and price depend on what your system actually contains
• It is retained knowledge because decades of business logic end up being documented rather than trapped in one person’s head
• It is control: you steer every meaningful decision, from what to keep to when to go live
• Above all, it is a revenue stream from the first day you release in production and a happy customer base

 

We already see this in practice. For a European vertical market software provider running a broad operations platform, a one-week YMF proof of concept led to a roadmap projecting roughly half the engineering hours of their own traditional estimate.

Want to know where you stand? Ask yourself three questions:

• who holds the domain knowledge
• how will you measure the gap with your legacy system
• and have your AI agents been evaluated

If the honest answer to any of them is “we don’t know”, that is exactly where we start. Because with AI, you can delegate intelligence, but you cannot delegate understanding.

Give me, Remus, or your regular Yonder contact a call to discuss how the YMF could work for you and how you can build a foundation to continue your software business now and in the future.

Cristian Inceu
Managing Director and Player-Coach

 

Go directly to our YMF solution overview.