Staging and production drift
A common failure point is a staging environment that looks nothing like production, so bugs and configuration differences surface only after a release reaches real users. Differences in instance sizes, environment variables, database schemas, dependency versions, and data distributions make staging tests unreliable. The challenge is closing that gap so that what works in staging is a meaningful predictor of what will work in production, which requires disciplined parity in configuration, data, and infrastructure definition.
