Just earlier today I happened to write about Mir Development Stats Dominated By Canonical. There's been 16 Canonical developers working on the Mir code but only seven of them have more than 100 commits to Mir.
Olli Ries, the fellow Bavarian beer drinker who turned from working at SUSE to Canonical, posted about new job openings involving Mir and Unity. Most of the positions are about Unity work, but they also want at least another developer to engage in "developing a technology that is set to replace X.org and will be the foundation for the work on newer form factors."
For their Mir software engineer they are looking for someone that's great at C++, knows how to use the CMake build system, experiences with performance/robust/application-architecture designs, has experience with Linux development, and is experienced with OpenGL. Past experience with X.Org or Wayland isn't mentioned at all on the page.
The Unity engineers they want are for working on the Unity APIs and Unity user-interface, as well as a quality engineer working on the UI.
Olli says, "The team is set to provide an alternative to X.org – an opportunity and challenge at the same time (they always go hand in hand anyways;). An undertaking like that requires the finest software engineers, trying to replace a 30y old & mature technology in a short amount of time does not give much room to err." Hit up Olli's blog for the job links if you want to take on this challenge.