An international website can retain enquiry links in old emails, distributor systems and printed material long after its application infrastructure changes. A replacement endpoint must therefore do more than display the current homepage. It has to preserve the requests those existing links and integrations still make, or provide an explicitly planned replacement for them.

For teams operating containerised services on Amazon ECS, the October 20 introduction of ECS Gateway offers an incremental adoption path. AWS says an existing service can add a gateway connector while retaining its current load-balancer path, allowing the new connection to be validated before the old configuration is removed. This is an option for that technical stack, not a recommendation that other export websites change hosting.

While both paths remain available, identify which requests still use the previous endpoint and which have been validated on the replacement. That comparison defines the remaining migration work.

Define the requests that must survive

Begin with what the existing service receives: product reads, document downloads, form submissions and any external callbacks still in use. These paths do not all need the same test. They do need to remain visible in the cutover plan. A basic health endpoint may return a successful response while a real enquiry loses a field or reaches an unintended application configuration.

Gateway provisioning and an ACTIVE route establish that traffic can reach the service through the new path. They do not establish that the application processes every supported request correctly. Host and path handling, identity propagation, validation and downstream storage can each introduce a difference after the network connection itself is working.

For a Chinese manufacturer whose overseas sales team depends on the site, this is where the business review should become specific. Which forms carry model and application details? Which download links appear in ongoing discussions? Which integration expects a particular response? The questions should refer to requests the service actually supports, rather than a generic checklist copied from a different website.

Use consistent, non-sensitive test inputs to compare the routes. For read operations, verify the returned product, version and state. For operations that create records or send notifications, arrange controlled test objects and stable request identities before exercising them. Sending the same real buyer enquiry through both endpoints would manufacture duplicate work during the test. Parallel availability does not mean every production write should be duplicated.

Keep a fallback until the differences are understood

If the two paths behave differently, identify the layer responsible before deleting the old resources. The mismatch may concern routing, application settings, authentication context or a subsequent service call. Preserving the existing path provides a known route while that distinction is investigated. Removing it first turns a comparison into an urgent recovery problem.

AWS also describes deployment-time re-evaluation of gateway associations. Services connect to newly compatible gateways and lose routes for gateways that have been disassociated. A deployment can therefore change the effective connections after an earlier validation. The acceptance record should describe the paths actually present, rather than relying on a gateway name written into a previous handoff document.

There is no universal number of days after which an old enquiry endpoint becomes safe to retire. The relevant conditions are coverage of the supported requests, remaining external references and an agreed fallback. A long period of coexistence without observing the old route can provide less useful evidence than a shorter, well-scoped comparison. Duration is not a substitute for knowing what still depends on the endpoint.

The service owner should decide what retirement includes. Removing a load-balancer association, ending an old hostname's role and updating a link in a distributor system are not automatically the same action. Confirm the intended scope before removing resources, and keep responsibility for any references that remain outside the application's direct control.

Make temporary unavailability visible

If cutover requires an interruption, coordinate it with the approach described in planning maintenance responses and recovery checks. A successful-looking placeholder can hide the fact that buyers cannot submit an enquiry. After restoration, test the actual business entry points, not just the deployment task's completion status.

A useful final handoff can identify the requests tested, the downstream records observed and the route available if the new path fails. It can also identify any old references still being retired. Once those facts are established, removing the previous connection is a controlled change rather than a conclusion drawn from the appearance of a webpage.

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