I believe there are two questions that we need to answer. The first question is how do you organize your team? The second part is, given the first answer, how do you organize the work for the team?

The way I am doing it at the moment, my team is a unified team that includes design as well as development and testing/evaluation. We put all the work on the same board, regardless of which type of work it is. So “doing” could refer to design tasks, coding tasks, or evaluation/planning tasks equally. We tag each ticket with the type of task that it is in order to tell them apart. So far it’s working quite well at making the “whole work” visible.

You might like to consider this as an alternative to specific columns to each type of task. It’s a simpler board, it allows for a wider variety of task types, and it more easily accommodates rework and revision. Something to think about.