When we first started coding together, Emmett and I would divide up tasks. Justin writes the week view calendar, Emmett writes the contact manager. Justin writes the login system, Emmett writes the user settings page. Eventually, what we found was that I would continually go to Emmett for help on things that I was worse at (hard algorithmic problems, fundamental design decisions), and he would leave for me to do things that I was good at (making widgets actually work, testing). At some point, we decided that instead of splitting a project up into pieces and each taking some distinct set, that Emmett would prototype and write the initial version of almost everything (the first 90%) and I would clean it up to the point where it was actually working and usable (the second 90%).