Stack Lighting created a spatial intelligence platform to track activity for indoor spaces. The platform was an end-to-end system based on embedding Doppler radar into light bulbs, then aggregating and analyzing the data in the Stack Lighting cloud. With both control and machine learning layers, the insights were available through a robust set of APIs allowing real-time and responsive applications to be created. Applications were developed for home and building automation, as well as services such as security, space usage analytics and healthcare. Stack Lighting shipped multiple consumer and commercial products as well as enabled partner manufacturers and service providers to expand their offerings with the technology. Stack Lighting was acquired by Philips Lighting in 2017.