The IT Department Headache
These systems prevent upgrades, require expensive workarounds, and hold entire organisations hostage to a technology stack that the rest of the world moved on from years ago. The people who understand them are often a single developer deep. When that person leaves, the knowledge goes with them. The risk is real, and it grows every year.
The Bottleneck Is No Longer Coding.
Since December 2025, TCB Consulting has embedded AI into its entire development lifecycle. This transformation has fundamentally changed the economics of rebuilding straightforward legacy business systems. The bottleneck in software development is no longer coding; it is analysis and design. This is precisely where TCB has always been strongest. By utilising AI-assisted development tools, we can port the business logic of your legacy systems into modern, secure, full-stack Single Page Applications (SPAs) at a fraction of the traditional cost and in a fraction of the time.
This applies to straightforward legacy business systems — the kind that run on Access, Excel, or ageing bespoke platforms. We are not rewriting SAP. But if your critical system runs on something that a modern SPA could replace, the conversation is worth having.
A Structured, Proven Approach
Analyse
We analyse the existing legacy logic and document the business processes it supports. This is our traditional strength, and it is where the work that matters most happens.
Rebuild
We use AI-assisted development to accelerate the rebuild into a modern, secure, full-stack SPA, preserving all essential functionality. This is not vibe coding. The foundation of the rebuild is a rigorous design document produced by back-modelling the legacy system — understanding precisely what it does, why it does it, and how it must behave before a single line of new code is written. AI supports the construction work; our consultants retain control, oversight, and direction throughout. The result is a system we understand completely and can properly support.
Prove
We rigorously test and prove that the new SPA fulfils the exact same function as the legacy system. Nothing is signed off until the equivalence is demonstrated.
Deliver
We deliver a commercial-grade application that meets strict corporate and government security and style standards.
We Took Our Own Medicine First.
Grassroots
Our own comprehensive HR and payroll package for Jersey, Guernsey, and the Isle of Man. We modernised it ourselves before offering this service to clients.
Critical Operational System
A critical operational system we currently maintain for a client, successfully rebuilt as a modern SPA with full functional equivalence preserved.
Eliminating Vendor Dependency
A client transitioning from a legacy Software as a Service product to an equivalent new bespoke SPA — eliminating vendor dependency and reducing ongoing costs.
Built to Last. Supported to Stay That Way.
A new system is only as good as its ongoing support. Every modern SPA we build comes with a comprehensive maintenance contract. This ensures your new system remains secure, up to date, and fully supported long after the initial rebuild is complete. Because our process is AI-assisted rather than AI-driven, we retain full knowledge of what was built and why. Our consultants directed the work; they understand the system; they can support it. You are not left holding a system that only an AI account can explain. You are gaining a long-term technology partner who knows your system inside out.
Tell us about your legacy risk.
We will tell you what it would take to fix it. No jargon. No obligation.
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