The evidence that built trust where there was no hierarchy

An integration error caused false positives between our platform and a client's banking core. Without formal authority over the responsible external vendor, irrefutable technical evidence —not hierarchy— is what got both sides to collaborate on the fix.

The symptom: "lost" operations

I was working on the integration between our platform and a bank's core system when we started seeing something odd: an intermediate component, under certain scenarios, confirmed receipt of a transaction without actually ingesting the file. To the client, that looked like lost operations. To us, technically nothing had failed on our side — which, in practice, didn't matter to anyone on the other side waiting for their transaction to appear.

The real problem: no formal authority over the vendor

The case escalated to the bank's IT deputy directorate, which requested a joint effort between us, the bank, and its banking-core provider to diagnose and design a solution. The real problem was that I had no formal authority over that external vendor's technical team — I couldn't demand anything from them.

Building irrefutable evidence

The only thing I could build was irrefutable evidence. My team and I isolated the exact capture scenario generating the ingestion errors and shared it directly with the vendor's technical team. There was real resistance in the early conversations — nobody wants to hear that their system is the cause of an effect visible to the end client. But once we walked them through the evidence, step by step, both sides agreed on a clear division of actions: the vendor implemented error handling on their side, and we attacked the root cause in the capture flow to rule out the hypothesis that responses were simply being lost in transit.

Real trust, not professional courtesy

The result, between both fixes: we mitigated the false-positive problem and significantly reduced reports of missing orders. What mattered most wasn't only the technical fix — it was that the trust built was real, not just professional courtesy, and it showed in how the vendor's willingness to collaborate changed on the topics that came up next.

The lesson

The lesson I take, and keep applying on every Barajas Advisory project: without formal hierarchy over the other party, irrefutable evidence is the only currency that truly builds trust and moves a fix forward.