TeC is a framework for end-user design, deployment, and evolution of applications for smart spaces. Design is declarative and focuses on simple tailoring of behavior and on interconnection of devices such as motion sensors, cameras, thermostats, and smart electric meters. TeC apps act as teams of elements with no central control: elements play their roles autonomously, and app behavior is emergent. Under the hood, the operational semantics promotes resiliency: the failure of any element may cause degraded operation of the features that depend on it, but all others remain operational. Automated (re)deployment of TeC designs allows users to keep evolving their apps as they buy new gadgets or change their minds about features.