When to Integrate vs. Replace a Legacy System
Replacing an old system outright feels like progress, but it's often the riskier and slower path compared to integrating around it first.
When a legacy system is causing real pain, the instinct is often to replace it entirely. But a full replacement means the new system has to match every behavior of the old one on day one — including the undocumented edge cases nobody remembers deciding on.
Integrating around a legacy system first — building new interfaces or automations that talk to it via its existing data, exports, or a thin API layer — lets you address the most painful parts of a workflow without betting the whole operation on a single cutover.
This also creates a natural, lower-risk migration path: once the new layer has been running in production and proving itself, migrating the underlying system becomes a more contained decision, made with real usage data instead of assumptions.
Full replacement is sometimes the right call — particularly when the legacy system is a genuine security or compliance liability. But it should be a deliberate decision made after understanding what the system actually does today, not the default first move.