Production Bugs Stem From Runtime State, Not Faulty Code, Argues Engineering Piece

A DEV Community article argues that senior engineers often find that the code behind a production failure looks correct, because the bug arises from a runtime state its author did not anticipate. The piece describes such bugs as collisions between locally correct logic and unexpected inputs, such as a collection emptied on an unusual path or a value stored with the wrong type after a migration. It explains that a stack trace shows only where an error surfaced rather than where it originated, and that the source code shows the logic but not the conditions that triggered the failure. The author contends that the runtime state, which is rarely recorded, is the layer that actually holds the answer to a bug.