01 / Telecom · Customer UAT · September 2026
The response was ready.
So why wouldn’t it send?
A downstream system had returned its result. The qualification API had built its response. But an internal call had overwritten the HTTP status, preventing the response from reaching the caller.
My roleInvestigation, correction & retest coordination
Successful UAT retestSynchronous responses restored
Java / WSO2REST APIs · OpenCode-assisted diagnosis
Follow the response.
Simplified example with synthetic data.
Not a replay of a customer system.
- 01Customer systemSubmit qualification request
- 02Downstream serviceReturn the business result
- 03Integration layerBuild the outgoing response
- 04Internal data-service callChanges the outgoing HTTP status
- 05Response boundarySend the response to the caller
- Business result
- Pending
- Response body
- Not built
- HTTP status
- Not set
- Delivery
- Waiting
The caller asks whether a service can be provided. The response still needs to be assembled.
The boundary I own
I own the integration layer connecting operators’ northbound CRM, ordering and sales systems to downstream orchestration, provisioning and activation systems, and network elements. This failure appeared during a customer’s preproduction qualification testing.
Separate the symptom from the cause
An installation issue initially obscured a separate response-path regression. I gathered logs, installed versions and live configuration through a delivery colleague, and used OpenCode to compare working and failing execution paths.
The investigation changed direction when qualification still failed after the installation issue was resolved. I challenged the interim explanation against fresh evidence and traced the outgoing status to the internal data-service call.
Correct the boundary, then verify
I provided two corrected qualification sequences, restoring the intended HTTP status before the response was sent. Both XML files passed syntax parsing. I supplied reload guidance, requested retesting and received confirmation that synchronous qualification worked.
The delivery colleague confirmed that synchronous qualification worked after the correction. I subsequently packaged the fix into a generic release.
The timeline includes overnight and clarification gaps; hands-on repair time was not measured. This was preproduction UAT, not a live-customer outage. Final package deployment and acceptance were not established.
What this work shows
Fault isolation across integration layers, active verification of AI-assisted reasoning, ownership of a correction, and coordination through a confirmed outcome.
Based on an internal incident timeline and colleague-confirmed UAT results. Customer names, source messages and implementation files are omitted.