[notapenny]

I think your example could be seen as designing as a team, its just one person who does the writing, but everyone who needed to be involved was involved.

On a smaller scale I've worked in teams where when someone picked up a story, for certain cases we would first do a rough outline of the implementation and then take that to one or two devs from the team, just to talk about how to tackle the problem. Not a meeting, just five minutes of "here's what I think would work". Its hard but good alignment before writing code really helps with finding the errors in a design.