The TODO column is an ordered list of things to do. The job of the developer is to pick tasks from the top and move them towards the right. The task of management is to keep the TODO column sorted, and prevent tickets from being stuck in any other column.
The task of management is aided by limits on how many items each column contains. Those limits are based on how many things people can realistically do at once.
I disagree. Who is sorting those tickets? Are they sorted arbitrarily or were the technicals considered? Is the ticket at the top feasible given the current state of the codebase/product?
In theory this would work, but it has the pre-requisite that whomever is managing tickets understands technology - which, in my 10 years in the field, has been quite rare.
They are sorted according to the project roadmap, usually by a person who understands business requirements, and a person who understands reality.
In my experience, it's usually done in a weekly meeting that involves a small subset of the team. We don't need to estimate tasks. We only need to know their logical order (dependencies) and priority (requirements). We don't need the whole team present for that.
If the requirements or reality change during the week, there is no cost to reordering the todo column. It doesn't change how much gets done, just in which order it gets done.
In my experience, the final sorting needs to be done by a collaboration between ticket manager and someone-who-understands-technology anyway. If the ticket manager doesn't have a clue, they can't make judgement calls necessary as for nontrivial software, it can be hard to say if this is one day or one year of work.
The TODO column is an ordered list of things to do. The job of the developer is to pick tasks from the top and move them towards the right. The task of management is to keep the TODO column sorted, and prevent tickets from being stuck in any other column.
The task of management is aided by limits on how many items each column contains. Those limits are based on how many things people can realistically do at once.