I will touch the general process of how the last two default themes were developed, how we went from the first design mockups to the final design and how even that changed over the last five months. Starting with research of what didn’t make it in the previous default theme and how the theme conversion from Twenty Twelve as a starting point worked, we will look at the ground work, feature development, and first round of theme breaking and bug fixes, before Twenty Thirteen was even introduced to core. Finally I’ll go over the time of intense breaking and fixing and (hopefully) the release, maintenance, and future upgrades.