people practice TDD as a mob, i.e. as a group of 5 people, plus-or-minus 1.
constraints change with each round, but they are not about how the code is written.
instead the constraints define how people in the mob communicate.
If you are interested in learning about mob programming, and specifically, differing styles of mob programming, and want to share these practices within your community, then please join us for one of the upcoming GLOBAL Day of MobRetreat events.