[gentoo-user] {OT} Development framework with access restriction?

[Grant]

I'd like to hire a freelancer to work on my website.  I don't want to
provide access to all of my code, but instead only the particular file
or files being worked on.  Does anyone know of a development framework
that would help facilitate that sort of thing?  Would no shell access
along with restricted SFTP access be the simplest, safest, most
effective way to go?

- Grant