Collaborative communities such as those building wikis and open source software often discover that their human interactions have just as many scaling problems as their web infrastructure. As the number of people involved in a project grows, key decision-makers often become bottlenecks, and community structure needs to change or a project can become stalled despite the best intentions of all participants. I’ll describe some of the community scaling challenges in both Wikipedia’s editor community and the development of its underlying MediaWiki software and how we’ve overcome — or are still working to overcome — decision-making bottlenecks to “maximize community throughput”.