  We present the design and implementation of a visual search system for real
time image retrieval on JD.com, the world's third largest and China's largest
e-commerce site. We demonstrate that our system can support real time visual
search with hundreds of billions of product images at sub-second timescales and
handle frequent image updates through distributed hierarchical architecture and
efficient indexing methods. We hope that sharing our practice with our real
production system will inspire the middleware community's interest and
appreciation for building practical large scale systems for emerging
applications, such as ecommerce visual search.
