The proof of concept looked perfect in code review. Locally, it behaved. In a staging sandbox, the output matched the spec. But the moment it touched a real user environment, with its unique configuration quirks, it collapsed. That moment is when “user config dependent” stopped being a vague risk and became a blocker.
A proof of concept user config dependent issue happens when the success of your prototype is tied to a specific setup—environment variables, hardware assumptions, dependency versions, device settings. The POC no longer proves the concept universally; it only proves it in one narrow context. If you miss that, you risk building the wrong thing faster.
This is not just about portability. It’s about truth. If your early validation only works under a developer’s preferences or a lab machine’s configuration, you’re stacking fragility into the foundation. And every layer you add on top multiplies the risk.
The fastest way to detect user config dependence in a proof of concept is to run it in multiple fresh environments immediately. Not later. Not after polish. Before deciding the idea works. Spin up a clean environment. Change config paths. Swap OS versions. Kill your assumptions early. The cost of catching user config sensitivity grows exponentially once you leave the prototype phase.