Migration from legacy languages to latest-generation .NET

The problem

Some software is 20, 30 or 40 years old — and still running. The real risk isn't technical, it's human and strategic: skills are disappearing from the market, build environments can no longer be installed, and every change becomes a feat.

The languages concerned, among others:

• COBOL (mainframes, accounting batches)
• Visual Basic 6 and advanced VBA
• Delphi / Object Pascal
• FoxPro / Visual FoxPro (end of support announced long ago)
• PowerBuilder
• Perl, RPG (AS/400), unmaintainable old PHP 4/5
• Basic in all its historical forms

Our approach: business logic first

Legacy software contains years of business rules — often nowhere else but in the code. Our method:

1. Business rule extraction: analysis of the existing code, interviews with users, and domain documentation before writing a single line. This is the most valuable step of the project.
2. Strategy choice, case by case: targeted rewrite, tool-assisted migration, or temporary encapsulation behind a modern facade while modules are replaced.
3. Rewrite in modern .NET: C#, ASP.NET Core, a clean SQL database — with current standards (automated tests, CI/CD, traceability).
4. Data migration: conversion and validation of historical data, with automated reconciliation between the old and new systems.
5. Parallel run: the old and new systems run side by side until everything is validated. A painless cutover.

What you gain

• Readable, maintainable code for any .NET developer on the market
• The end of dependency on one person or an unfindable technology
• A foundation ready for what's next: web, mobile, API, cloud
• Maintenance costs that go down instead of up

Who is it for?

Industrial companies, public administrations, SMEs whose critical tool rests on a dying language. Tell us about your system: we're used to reading code nobody understands anymore — and turning it into something clear.