The 404 Not Found status code represents a fundamental aspect of HTTP resource location and lifecycle management. Implementation requires careful consideration of user experience, SEO impact, and system architecture. Response handling should distinguish between different causes: mistyped URLs, deleted resources, or temporary unavailability. Logging and monitoring 404s is crucial for identifying broken links, content gaps, or potential security probes. SEO considerations include proper status code usage versus soft 404s, maintaining site maps, and implementing redirects where appropriate. Security implications exist - 404s can reveal information about valid endpoints, requiring careful response design. Error pages should be helpful without revealing system details, potentially offering search or navigation options. The 404 status code, while simple in concept, requires thoughtful implementation to maintain usability and security.
