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Legacy Application Modernization

The system everyone is afraid of is usually the one the business depends on most. We modernize it a slice at a time, with the old and new running side by side and a way back at every step.

Overview

Modernized in slices, with the business still running

Rewrites fail because they try to reproduce twenty years of undocumented behaviour in one go, while the business keeps changing underneath.

Instead we put a boundary around the old system, move one capability at a time behind it, and keep both paths live until the new one has proved itself in production.

Part of Enterprise Application Development
What’s included

Everything you need, nothing you don’t

A focused engagement, with the parts that usually get skipped left in.

  • An honest assessment: what to keep, refactor, replace or retire
  • A prioritised sequence based on risk and business value
  • The strangler pattern, so each slice is independently reversible
  • Behaviour captured as tests before anything is changed
  • Data migrated incrementally, with both sides reconciled
  • Decommissioning — the old system genuinely gets switched off
Why us

What is different about the way we do it

No big-bang weekend

Each slice goes live on an ordinary Tuesday, with a rollback that takes minutes.

Behaviour preserved deliberately

We write tests against the current system first, so "it used to do that" is caught early.

Business value first

We sequence by what unblocks the business, not by what is architecturally tidiest.

How we work

A clear path to something working

Short cycles, visible progress, and honest checkpoints where you decide what happens next.

Book a discovery call

Understand and measure

Code, data, dependencies and the real cost of leaving it alone.

Draw the boundary

A facade in front of the legacy system so consumers stop caring what is behind it.

Move a slice, prove it

One capability at a time, running in parallel until the numbers match.

Retire the old

Licences cancelled, servers switched off, savings realised.

Toolkit

Technology we bring

Modernization

Java.NETNode.jsPythonKubernetes

Data

change data captureDebeziumPostgreSQLSQL Server

Safety

contract testsfeature flagsparallel run
Also in Enterprise Application Development

Often needed alongside this

Let’s talk about your legacy application modernization.

Tell us where you are and what you need it to do. We will be straight with you about the shortest route there.