CDE Systems has the knowledge and experience to make old systems breathe new life.

And here’s the thing most people don’t expect us to say: your SQL Server database is probably fine.

A well-designed database from 2008 will still do the job. What’s usually holding the business back is the application sitting on top of it — the VB6 front end, the classic ASP pages, the Access screens, the desktop application that only runs on Windows and only inside the office.

So we’d rather replace that than start again. The data stays where it is.


What “legacy” usually turns out to mean

[IMG-1] — Layered diagram: SQL Server at the bottom, marked as staying; the application layer above it, marked as the part that changes; new web and mobile interfaces alongside. The whole argument in one picture.
Alt: Modernising the application layer over an existing SQL Server database

The application is old, the data isn’t. VB6, classic ASP, WinForms, Delphi, PowerBuilder, an Access front end, or a web application built on a framework nobody supports. It works, it’s just increasingly expensive to change and impossible to reach from outside the office.

Or the schema is the problem. Sometimes it genuinely is the database: no foreign keys, every column an nvarchar(255), business rules buried in triggers, tables that should have been three tables, and a data model that made sense for how the business worked in 2006.

Or the original developer has gone. The system works, nobody understands it, and every change is a gamble → legacy software rescue

We’ll tell you which of the three you’ve got, and they need very different answers.


Modernising what sits on the database

Over time the demands on an application expand and change. We re-engineer applications to improve ease of use, extend business utility and improve reliability — whatever their current state, quality or design.

Built with current technology — .NET and C#, Node.js, React and React Native — against the database you already have.


Modernising the database itself

Where the schema genuinely is the problem, it can be fixed in place rather than rebuilt.

Business logic moved out of triggers and into somewhere it can be tested. Data types corrected. Keys and constraints added so the database stops accepting data it should never have accepted. Tables restructured where they’ve been carrying three things at once. Stored procedures rationalised → T-SQL development and optimisation

All of it done incrementally, with the application still running.


Free review of your existing application

[IMG-2] — Right-aligned. A page of genuine analysis: schema diagram, dependency map, object inventory. Redacted. Shows the review is real work, not a sales call.
Alt: SQL Server application review and analysis

Before anyone talks about building anything, we’ll evaluate your existing application free of charge.

Send us a copy through our secure upload and our analysis covers every aspect of the design and construction: how it’s structured, where the business logic sits, what state the code and data are in, what’s holding it together, and what would change under each of the options above. Then we’ll ring you to talk through what we found and what we’d suggest.

From there, you’re free to decide what you want to do — including nothing.

arrange a review


The questions worth asking first

  • Is it better to replace the legacy application or extend its life?
  • Will keeping it operational be more or less cost-effective over the next three years?
  • How much effort is actually needed to migrate the platform?
  • How much effort is needed to re-engineer the application?

We’ll give you our answer to all four, including when the answer is that you don’t need us yet.


In stages, and reversible

Nothing here needs a big-bang cutover.

We take the thing that hurts most, build that, put it in front of the people who’ll use it, and get it working before starting the next. The existing system runs throughout. If you stop after phase one, phase one still works and still earns its money.

how we work



Related case studies

Not sure whether to extend it or replace it?

Send us the application and we'll tell you what we find, free of charge — including when the honest answer is that the database is fine and only the front end needs doing.

Send us the details → How we work →