Two Pizza Rule
🍕 A team should be small enough that it can be fed with two pizzas
In the early days of Amazon, Jeff Bezos instituted a rule: every internal team should be small enough that it can be fed with two pizzas. A smaller team spends less time managing timetables and keeping people up to date, and more time doing what needs to be done.
For any project: involve as many people as necessary but as few people as possible.