The document discusses lessons learned about ideal Scrum team size from a project with a team of 12 people that was too large. The large team led to issues like a huge backlog of over 300 points per sprint, endless refinement sessions, and difficulty focusing in sprint planning and reviews. The team was later restructured into smaller sub-teams to resolve these issues. In conclusion, while an ideal Scrum team size depends on the project, this team found their size of 12 people was too big and made process improvements by splitting into smaller groups.