While designed to make things easier for newcomers -- I think these features are actually some of the biggest culprits in making things _harder_ for newcomers, because they fail at so many edges, and when they do fail, there's so much magic going on that it's nearly impossible for a newcomer (or even an intermediate user!) to figure out what's going on and why.
I think the heavy emphasis on auto-loading was a mistake, that someone writing a new framework would be wise to learn from and not repeat.
The reloading in dev mode is HUGELY convenient, I have to admit so I have trouble calling it a mistake -- but is also a huge mess when it fails, and does not work under multi-threaded request dispatch. That latter will, I think, become an increasing problem as more people use multi-threaded request dispatch in Rails -- Rails4 has multi-threaded request dispatch on by defualt in production mode. But I think not in development mode, precisely because of the code-reloading problem. But I'm not sure diverging the dev and production environments (violating 12-factor, incidentally) is a good sustainable solution.
I think the heavy emphasis on auto-loading was a mistake, that someone writing a new framework would be wise to learn from and not repeat.
The reloading in dev mode is HUGELY convenient, I have to admit so I have trouble calling it a mistake -- but is also a huge mess when it fails, and does not work under multi-threaded request dispatch. That latter will, I think, become an increasing problem as more people use multi-threaded request dispatch in Rails -- Rails4 has multi-threaded request dispatch on by defualt in production mode. But I think not in development mode, precisely because of the code-reloading problem. But I'm not sure diverging the dev and production environments (violating 12-factor, incidentally) is a good sustainable solution.