404 Not Found is the most common error for many production web apps. So, many operations folks just start ignoring them after a while.
Turns out this can actually be very bad, as 404 errors often signal real production problems that CAN and SHOULD be fixed.
- Broken links to your site that are causing you to lose potential sales.
- Botched deployment / code changes that prevent your users from using your site correctly.
- Hacking activity that is wasting significant processing resources on your server.
Read on to learn about the 4 common classes of 404 Not Found errors that you should find and fix.