In most organizations, an effective team has a maximum size of around seven to nine people. Amazon, for instance, is known for limiting the size of its software teams to those that can be fed by two pizzas.4 This limit, recommended by popular frameworks such as Scrum, derives from evolutionary limits on group recognition and trust known as Dunbar’s number (after anthropologist Robin Dunbar). Dunbar found fifteen to be the limit of the number of people one person can trust deeply.5 From those, only around five people can be known and trusted closely.
