Maybe I’m just bit crap, but I do tend to think this underestimates the
length of time it takes by quite some way, and is in danger of making us
slowcoaches feel totally useless.
If you’ve got the app clearly thought through, understand the
architecture and UI, and have a good understanding of not just Rails but
Ruby too, and aren’t thoroughly developing test case prior to coding,
then these sort of timescales are possible.
However, there’s probably a day or two – at least, and that assumes no
diversions, checking RSS feeds, other flow-reducing activities etc –
working out how to structure the app if there’s any depth to it (though
it won’t necessarily be all at the beginning).
Add in a good dose of TDD, which will probably take 2-3 times as long as
writing the code itself (quit looking at the browser), and you’re
talking weeks not days.
However, at the end, it will still have been an order of magnitude less
than most other languages, and will probably be far more robust code
with a stronger, more elegant structure (particularly if, like me, you
come from PHP), and will have a good test suite that will make
refactoring a cinch.
Just my $0.02