For Australian organisations stuck on ageing software

Legacy System Integration Australia

You have an old system that still runs the business: an on-premise database, a line-of-business application, an ageing ERP. It works, your team knows it, and replacing it is expensive and risky. The problem is that nothing modern can talk to it, so data gets re-keyed or exported to spreadsheets by hand.

We connect that legacy system to your modern cloud apps without a rip-and-replace. We wrap the old system in a modern API and automation layer so it can exchange data with the rest of the business, running quietly alongside it. You keep the system that works, and the manual re-keying stops.

Book a Integration Call (03) 9003 0111

Realistic ROI

$50k to $500k+

Replacement cost deferred

Typical range for a full ERP or line-of-business replacement, integration is a fraction of that

5 to 20 hours per week

Manual re-keying removed

Realistic for teams exporting and re-entering legacy data, varies with volume

3 to 8 weeks

To a working integration

Most legacy connections go live in this window, depends on access method

Zero

Changes to the legacy system itself

The wrapper sits around it, the old system keeps running untouched

Why Wrap the Legacy System Instead of Replacing It

Ripping out a system that works is the most expensive and riskiest path. Four reasons wrapping it in a modern integration layer is usually the smarter first move.

No risky rip-and-replace

Replacing a core system is a multi-month, high-stakes project that often runs over budget and disrupts the whole business. Wrapping the legacy system in an integration layer is far cheaper and lower risk. The old system keeps running exactly as it does today, while data starts flowing to and from your modern apps.

We meet the system where it is

Some legacy systems expose a database, some only produce files, and some can only be reached through their screen. We pick the safest integration method available (database-level, file or secure transfer, or screen-level as a last resort) so we can connect even a system that was never designed to be integrated.

It buys you time before any replacement

A wrap-and-integrate approach takes the immediate pain away (the re-keying, the spreadsheet exports, the data living on an island) without forcing a replacement decision now. You can run for a year or more this way, then replace the legacy system later on your own timeline, with the integration layer easing the eventual migration.

We own the upkeep, you keep the knowledge

Many legacy systems are held together by one or two people who understand them. We document how the integration works and carry its maintenance, so the data flow does not depend on a single person, and your team keeps doing what it does without learning a new system.

How Legacy System Integration Works

Six stages from understanding the old system to a monitored integration that runs safely alongside it.

Access assessment

Assess the legacy system

We work out how the system can be reached: a database we can query, files it can export, or only its screens. We document the data we need, where it lives, and the safest way to read and write it without disturbing the system.

Method chosen

Choose the integration method

Database-level is cleanest where allowed. File or secure transfer (SFTP) suits systems that export batches. Screen-level automation is the last resort for closed systems. We pick the most stable method the system supports.

Modern API

Build the API wrapper

We wrap the legacy system in a modern API on a custom cloud automation layer. Your other apps talk to that clean interface instead of the old system directly, so the messiness of the legacy system is hidden behind a stable contract.

Clean exchange

Map and translate data

Legacy data formats are rarely modern. We translate codes, dates, and currency into AUD and Australian formats your cloud apps expect, and back again, with AI-assisted automation handling the inconsistent records old systems tend to hold.

Safe rollout

Run alongside, read-mostly first

We start read-only where we can: pulling data out of the legacy system into your modern apps, proving it is correct, before enabling any writes back into it. The old system keeps being the system of record until you are confident.

We own upkeep

Monitor and maintain

The integration is monitored for failures, file delays, and data anomalies, with same-day alerts. We maintain the wrapper as the cloud apps around it change, and as you eventually plan a replacement.

Common Legacy Integration Scenarios

Task	Traditional	With Yes AI	Notes
On-premise ERP feeds cloud reporting	Exported to spreadsheets, re-keyed monthly	Data flows automatically to the cloud	Legacy ERP data is read and pushed to a modern reporting or accounting tool, so leadership sees current numbers without a manual export ritual.
Old database synced with a modern CRM	Customers maintained in both, by hand	Records exchanged automatically	Customer and order data moves between the legacy database and HubSpot, Salesforce or Pipedrive, ending the double entry.
Closed line-of-business app with no API	Data trapped, copied off the screen	Wrapped and reachable	Where the system exposes nothing, careful screen-level automation reads and enters data, giving even a closed app a usable interface.
Batch files from an ageing system	Manually imported each day	Picked up and processed automatically	Files dropped by the legacy system to a folder or SFTP are collected, validated, transformed, and loaded into the target app on schedule.
Legacy system to Xero or MYOB	Invoices and payments re-entered	Posted automatically with checks	Financial records from the old system flow into Xero or MYOB, with validation so only clean records post and exceptions are flagged.
Two-way write back into the old system	Not attempted, too risky by hand	Controlled, logged writes	Once reads are proven, we enable careful writes back into the legacy system, each one logged and reversible, so updates flow both ways safely.
Aged software stays compliant	Manual checks, easy to miss	Data surfaced for oversight	The integration surfaces legacy data into modern tools where GST, BAS and audit checks are easier, reducing the risk of the old system being a blind spot.
A file or feed stops arriving	Noticed days later, if at all	Alert raised the same day	Monitoring detects a missing batch or a stalled feed immediately, so a quiet failure does not corrupt downstream data.

How We Keep Legacy Integration Low-Risk

The legacy system is never modified

We do not change the old system. The integration sits around it as a wrapper. If you ever switch the integration off, the legacy system carries on exactly as before, with nothing to unpick inside it.

Read-only first, writes only when proven

We start by reading data out and confirming it is correct in your modern apps. Writing back into the legacy system is enabled only once reads are trusted, and every write is logged and reversible. This protects your system of record during rollout.

Database-level access used carefully

Where we query a legacy database directly, we use a read-focused account, avoid locking or load problems, and never write to tables the application owns without the vendor-supported path. We confirm the safe approach before touching production data.

Screen-level automation is the last resort

For closed systems we can automate the user interface, but it is more fragile than an API or database, so we treat it as a fallback. We build in checks and alerts so any UI change is caught quickly rather than silently producing bad data.

Backups and a clear rollback path

Before any write-enabled go-live, we confirm the legacy system is backed up and agree a rollback plan. If anything looks wrong, we can pause the integration and restore a known-good state without drama.

Privacy Act 1988 and on-premise data residency

Legacy systems often hold sensitive records on-premise. We handle data under the Australian Privacy Principles, keep it within the boundaries you require, and document exactly what the integration reads, writes and stores.

How Yes AI Helps Organisations on Legacy Software

Access and risk assessment

We assess how your legacy system can be reached, what data matters, and the safest integration method. You get an honest read on what is possible, the risks, and a fixed-price plan, whether or not you proceed with us.

Build the wrapper and integration

We build the modern API wrapper and the connections to your cloud apps on a managed cloud automation layer. The legacy system stays untouched, and your other tools talk to a clean, stable interface.

Cautious, staged rollout

We start read-only, prove the data is correct, then enable controlled writes. Each stage is verified against your real data before the next, so the system that runs your business is never put at risk.

Maintenance and migration runway

We monitor and maintain the integration, and when you do decide to replace the legacy system, the wrapper and the data mapping make that migration far smoother. We can run the eventual data migration too.

Our 5-Step Legacy Integration Rollout

Most legacy integrations reach a working state in 3 to 8 weeks, depending on how the old system can be accessed.

Assessment and method (week 1 to 2)

We assess access methods, map the data, agree the safest approach (database, file or screen-level), and confirm backups and rollback. Spec and risk plan signed.

Build the wrapper (week 2 to 4)

We build the modern API wrapper and the connections on a managed cloud automation layer, tested against a copy of the legacy data so production stays untouched.

Read-only go-live (week 4 to 6)

Data flows out of the legacy system into your cloud apps. We confirm it is correct and complete before enabling any writes back.

Controlled write-back (week 5 to 8)

Once reads are trusted, we enable careful, logged writes into the legacy system, monitored closely, with the ability to pause instantly.

Maintenance and migration runway (ongoing)

We monitor and maintain the integration and stand ready to support an eventual replacement, using the mapping we built to ease the migration.

FAQ

Our system has no API at all. Can you still integrate it?

Usually, yes. We look for the cleanest available path. If there is a database we can query safely, we use that. If the system can export files, we pick those up by secure transfer or a watched folder. If it can only be reached through its screens, we can automate the user interface as a last resort. Even a closed, old line-of-business application can almost always be given a usable, modern interface around it.

Will connecting to it put the old system at risk?

We design specifically to avoid that. The legacy system is never modified, the wrapper sits around it. We start read-only, prove the data is correct, and only enable writes once you are confident, with every write logged and reversible. We confirm backups and a rollback plan before any write-enabled go-live. The system that runs your business keeps running throughout.

Is this cheaper than just replacing the legacy system?

Almost always, and dramatically so. A full ERP or core-system replacement is typically a $50k to $500k or larger project that disrupts the whole business for months. Wrapping the system in an integration layer is a fraction of that and takes weeks, not months. It removes the immediate pain (the re-keying and the data island) without forcing a replacement decision now.

Does this lock us into keeping the old system forever?

No, the opposite. The integration buys you time and actually makes an eventual replacement easier. The data mapping and the clean API we build are exactly the assets a migration needs, so when you do decide to replace the legacy system on your own timeline, you start from a much better position. We can run that data migration for you when the time comes.

Only one person here understands the old system. Is that a problem?

It is a common situation and one reason this work is valuable. We document how the integration reads and writes the legacy data, so the data flow no longer depends on a single person's knowledge. We engage that person during assessment where we can, but the goal is to reduce the bus-factor risk, not increase it.

Can it run alongside the legacy system without downtime?

Yes. The integration is designed to run quietly alongside the old system while it stays the system of record. We typically start by reading data out during normal operation, with no downtime, and schedule any heavier work for quiet periods. The aim is that day-to-day users of the legacy system notice nothing change except that the data now appears in their modern tools.

Is sensitive on-premise data kept secure and onshore?

Yes. We handle all data under the Australian Privacy Principles and the Privacy Act 1988, use least-privilege access to the legacy system, and keep data within the residency boundaries you require. We document exactly what the integration reads, writes and stores so your compliance team has a clear picture.

Connect Your Legacy System Without the Risk

Book a integration call. We assess how your old system can be reached, what is possible, and give you a fixed-price plan to connect it to your modern apps without a rip-and-replace.