When any successful project attracts a large community, there will be growing pains. Since its launch in 2015, the experimental cloud computing testbed Chameleon has realized its vision of becoming a shared scientific instrument for computer science research and education. The project, led by Argonne Senior Scientist and UChicago CASE Affiliate Kate Keahey, has supported over 800 projects and 6,000 users from around the world and developed several new applications and deployments.