Legacy system connectivity
Connect the system you still need to run.
Expose controlled interfaces around existing systems so new applications can be introduced in stages.
Existing records and business behaviour
Validation, translation and controlled access
A stable contract for new capabilities
Stop spreading internal database assumptions
The fragile approach
Let every new application query the old database
Schema details become external contracts and changes become harder to control.
The intended approach
Introduce one supported integration boundary
Translate data in a dedicated adapter, monitor failures and isolate consumers from internal changes.
Integration & business systems
Protect the old system behind a supported boundary.
Interface discovery
Identify supported exports, database access and application interfaces before choosing a connection.
Adapter boundaries
Contain legacy formats and assumptions within an adapter that exposes a documented contract.
Safe synchronisation
Plan batching, replay and reconciliation around the existing system’s capacity and ownership rules.
An implementation example
Connect what works without exposing what is fragile
Use an adapter to protect consumers from inconsistent formats, old authentication or limited availability. Start with the access the system can safely support.
A safe boundary around an older system
An order platform must update its database and publish an integration event reliably.
A failure to account for
The publisher crashes after sending the event but before marking it complete.
Illustrative scenario, not a customer case study.
From implementation to ownership
What your team receives
Agree the scope and the acceptance evidence before delivery starts.
Adapter contract
Supported operations, data meaning and access limitations.
Included scope agreed before deliveryConnectivity implementation
Controlled translation, validation and failure isolation.
Included scope agreed before deliveryOperating notes
Monitoring, transfer timing, recovery and known constraints.
Included scope agreed before deliveryEvaluate supported exports, scheduled transfers or controlled database access. Document the limitations and avoid unsupported writes that bypass business rules.
Discuss legacy system connectivity
Bring the workflow, the constraints and the questions your team needs to resolve.