Check out this wild Copilot suggestion that actually compiled and worked.

Yes, exactly. That first-order vs second-order cost framing is crucial.

We saw this during a SaaS migration. The team saved a week using generated scripts to map customer data. But those scripts had no validation stage, no row-level error logging. When we hit a format mismatch, the entire batch just silently stopped. The "budgeted" week of dev time vanished into a weekend of forensic work and a delayed launch.

The real cost wasn't the delay. It was the eroded trust from the business team who now sees the migration as risky. That's a third-order cost these tools will never calculate.

Yeah, that "it worked" moment is what makes me nervous too. I just trust the syntax check and the green test, then move on.

I'm not a deep backend person, so I'd have no idea if that secure random instantiation was heavy. But it makes sense. The performance hit wouldn't show until way later.

Your last question hits home for me. If it can get something this complex looking right, what simpler things is it messing up in my spreadsheets or project templates that I'd never think to double-check? The trust builds quietly.

That's such an underrated point. It moves the risk from legal to strategic, which is so much harder to unwind.

I've seen this exact scenario play out with a third-party payment gateway. The generated code handled their non-standard idempotency keys perfectly. It was clever, it worked. But it meant our entire transaction flow was structured around *their* idea of a retryable error. When we later tried to add a second provider for redundancy, the architecture couldn't support two different failure models. We were stuck.

You don't realize you've adopted a vendor's worldview until you try to leave it.

Whoa, that's a crazy example. The "it works" moment really is the trap, isn't it? It feels like a win, so you stop digging.

A follow-up that's probably naive: for someone like me still learning, how do you even start checking the performance stuff? Like, do you need to load test every piece of generated code just in case now? That seems impossible.

Totally agree about the mental model gap. It's like having a well-tuned engine blueprint but no understanding of thermodynamics - you can't diagnose the knock under heavy load.

I ran into a similar issue with generated gRPC interceptors for tracing. The code perfectly injected span IDs and followed the OpenTelemetry spec, but it had no sampling logic. In development, with low traffic, everything looked great. In production, the trace volume exploded and crashed our collector. The tool gave us the "how" but completely missed the "when" and "how much".

That brittle sophistication is the perfect term for it. The system fails in ways that look like infrastructure problems, not logic errors, so you burn cycles checking your monitoring setup instead of the generated code.