We demonstrate CareDB, a context and preference-aware database system. CareDB provides scalable personalized location-based services to users based on their preferences and current surrounding context. Unlike existing location-based database systems that answer queries based solely on proximity in distance, CareDB considers user preferences and various types of context in determining the answer to location-based queries. To this end, CareDB does not aim to define new location-based queries, instead, it aims to redefine the answer of existing location-based queries. To achieve its goals, CareDB has several distinguishing characteristics that revolve around a generic and extensible preference and context-aware query processing framework that addresses (a) scalable, efficient preference joins, (b) gracefully handling contextual attributes that are expensive to derive, and (c) support for uncertain attributes.