Slapping up a slop website is no threat to professional tech folk.
When they have full DevOps, with multiple environments for testing, compliance with security best practices, can do database updates and data migrations, move the app smoothly between different platforms, streamline costs, and scale to at least hundreds of thousands (if not millions) of users without crashing and burning... then go ahead and worry. We aren't anywhere near that.
On the other hand, if you are purely a coder, and cannot run a project that does all of the above... maybe start your worrying earlier.
When they have full DevOps, with multiple environments for testing, compliance with security best practices, can do database updates and data migrations, move the app smoothly between different platforms, streamline costs, and scale to at least hundreds of thousands (if not millions) of users without crashing and burning... then go ahead and worry. We aren't anywhere near that.
On the other hand, if you are purely a coder, and cannot run a project that does all of the above... maybe start your worrying earlier.