Nice idea. I realize at this point you're just trying to feel the waters and measure demand. Good for you. But even for a first iteration landing page, I think you need to demonstrate more awareness of how hard it is to outsource software development (even in small morsels).

Submit > payment > success just doesn't convince me, on the contrary, it makes me wonder if you ever delegated software development tasks to others. Not counting issues such as domain knowledge and integration, that were already mentioned by others, communication is extremelly tricky. For small-sized jobs, producing a full specification of both funcional and non-funcional requirements and going through a few cycles of submit-review-resubmit can take more time than required to just do the job myself.

With all those caveats, I would have use for services like these as well and I hope you can do a good job of communicating why someone would go to Codacy instead of Odesk, Freelancer.com or RentACoder.