Why nginx ignores your config order: rewrite, try_files, and if explained

A developer has documented two common nginx misconfigurations that stem from assuming the server processes directives strictly top to bottom. In the first case, pairing a rewrite directive with try_files in the same location block causes unexpected 404 errors because try_files never gets evaluated after a 'last' rewrite flag triggers a new location search. In the second case, placing an add_header directive inside an if block silently drops any add_header directives defined in the outer location block. Both issues arise because nginx processes each request through a fixed sequence of internal phases — such as rewrite, precontent, and content — and a directive's phase is determined by its type and placement in the config, not by its line number. Understanding this phase-based execution model is key to writing nginx configs that behave as intended.