SERVICE · LEGACY SYSTEM MODERNISATION
15+ production systems migrated. 30+ years combined experience. Quickway, Corporate Bodies, WesHealth.
The old system is not the problem. The plan to replace it in one weekend is.
Most legacy modernisation projects fail the same way. A 12-month build runs for 24 months. The new system goes live before it is ready because the old one is being decommissioned on a date that cannot move. Half the workflows do not transfer. Three months of business knowledge gets lost in the cutover. The team that knew the old system has moved on. Six months later you are paying a different consultancy to fix what the first one broke.
We do not work that way. Every legacy modernisation we run is phased. The old system stays live. The new system gets built alongside it. We migrate workflows one at a time, prove each one in production, and only retire the old equivalent once the new one has earned the right to replace it.
This is slower to start, faster to finish, and dramatically less risky. It is also the only approach we have ever seen actually work on a business-critical system. A clean parallel-run beats a clean cutover every single time.
The honest moment most consultancies skip: sometimes the right answer is to leave the legacy system alone. If it works, if it is stable, if the business knowledge inside it is documented, and if it integrates with the rest of your stack, replacing it for the sake of “modernisation” is a vanity exercise. We will tell you that directly. Modernise the parts that are actually blocking you. Leave the rest until they earn replacement.
If you have an old system holding your operations together and you do not know how to safely replace it, call 0431 000 062.
Legacy is a problem you can usually feel before you can name it. These are the patterns that tell you the system is past its useful life.
DIAGNOSTIC
If you recognise two or more, you are not deciding whether to modernise. You are deciding whether to do it on your timeline or on the system’s.
We treat legacy modernisation as a series of small, low-risk migrations rather than one large one. The shape is always the same. The detail varies by system.
Before anything else, the existing system has to be stable enough to run on while we build the replacement. This usually means a backup strategy, a snapshot of source code into a repository under your control, and a documented runbook for the next 12 months. Nobody migrates a system that is also having a crisis. Stabilisation is unglamorous but it is the foundation on which everything else stands.
We extract the business logic from the old system into a clear, documented specification. This is the hardest part of any modernisation. Most legacy systems have business rules nobody has written down, including the original developer. We interview operators, read code, run sample transactions, and capture every rule on paper. The specification becomes the contract between the old system and the new one. If a workflow in the new system does not match the rule in the specification, the new system is wrong.
We rebuild one workflow at a time, on a modern stack (Symfony in your cloud, fully owned by you, or on Nexus if a platform fit makes more sense). Each workflow goes live in parallel with the legacy equivalent. Both systems run for a period. We compare outputs. When the new system matches for a defined period, the old workflow is retired. Repeat until done.
The old system gets switched off only after the last workflow is proven on the new system. Decommissioning is the last step, not the first. By the time we pull the plug, nobody on your team has used the old system for weeks. The data is archived, the runbook is closed, and the migration is over. This is the only safe way to retire a system that runs a business.
We structure legacy modernisation engagements one of three ways. All three start with the audit.
Call 02 8964 5333 to discuss which shape fits your situation.
Three legacy programmes. Named clients. Real outcomes. Most are happy to take a reference call.
Modernisation is not the work for a junior consultant. The risks are too specific and the institutional knowledge involved is too easily lost in handover. You work directly with the two engineers who will plan, scope, and execute the programme.
Nicolas Wendell
MANAGING DIRECTOR
Nicolas has been building custom software since leaving school, bringing a lifelong passion for development to every project. Before founding Paladine Systems, he ran his own video game studio and earned multiple accolades in network engineering. Known as a driving force in the custom software world, Nicolas combines deep technical expertise with visionary leadership – guiding Paladine in delivering innovative, enterprise-grade solutions.
Mark Morcom
SENIOR SYSTEMS ENGINEER
Mark is a young prodigy in software development, bringing 5 years of experience to Paladine. Equally at home on the front end and back end, he crafts clean, scalable solutions that power complex applications. Mark’s sharp problem-solving skills and passion for innovation make him a driving force behind Paladine’s most advanced projects.
Five named stages. Each one is fixed scope and fixed price. You can pause between any two stages without losing progress.
AUDIT
1 to 2 weeks. Written audit, prioritised rebuild plan, fixed phase quotes.
STABILISE
2 to 4 weeks. Backups, source control, runbook, disaster recovery plan.
EXTRACT
2 to 6 weeks. Business rule documentation, test data sets, target architecture.
REBUILD
3 to 9 months. Workflow-by-workflow rebuild, in parallel with legacy.
DECOMMISSION
2 to 4 weeks. Final cutover, archive, sign-off.
Most clients run the whole programme over six to 12 months. The work scales to the size of the legacy system. We will not promise a six-week rebuild of a system that took ten years to write. We will tell you exactly what is realistic.
Six to 12 months for a typical mid-market system. Larger systems can take 18 months. The duration is set by the number of workflows, not the size of the database. A system with one core workflow and a lot of data is faster than a system with 20 workflows and very little data.
No. Phased modernisation means the old system runs the entire way through. We only retire it after the new one has earned its place. Across 15+ rebuilds, our clients have collectively experienced zero days of unplanned downtime during cutover.
Almost always. We have modernised systems built on Access, Visual FoxPro, Filemaker, Oracle Forms, custom PHP, classic ASP, and proprietary platforms with no documentation. If it stores data and the data is reachable, we can extract from it. The audit confirms the extraction approach before you commit to a rebuild.
Two options. Symfony in your cloud account if you want full ownership of source code and infrastructure. Nexus if a platform-hosted option is a better fit. We will recommend in the audit. Most clients pick a hybrid (Symfony for the core, Nexus for the integration layer).
Yes. Symfony builds are 100% yours, including source code, infrastructure, and intellectual property. Any competent dev team can maintain what we build. Nexus deployments are hosted by us, but your data and your business logic are always yours. No lock-in either way.
The audit will tell you which two or three phases give the most leverage. Many clients start with just the highest-impact phase and stop there. The phased model means you can pause between phases without losing progress. Some clients have run the audit, executed phase one, and paused for 18 months before commissioning phase two.
It stays in both systems during parallel run. We migrate data forward, validate it against the legacy source, and run write-through patterns where both systems stay in sync until the legacy workflow is retired. No data is lost. No data is left behind. Historical archives are preserved.
Call 02 8964 5333 or book a legacy audit below. The first conversation is free and is run by an engineer, not a salesperson. We will tell you whether modernisation is the right next step. Sometimes it is not, and we will say so.
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