Imagine a world where your home knows exactly where you are, realizes that you are going to the fridge for a midnight snack and turns on the night light. The rescue personnel know how many individuals have evacuated the residence during an emergency and the HVAC system operates more efficiently by knowing the inhabitants’ locations. Such ambient assisted living requires functional Indoor Positioning System (IPS). While outdoor positioning (e.g., GPS) is a mature technology, it does not work reliably inside buildings. Researchers have been working hard for the past two decades to develop robust, affordable IPS. In order to be successful, IPS needs to follow the GPS ethos, the end-user should not be required to deploy significant additional infrastructure resources. The rapid adoption of Internet of Things (IoT) means ubiquitous presence of networked devices and ambient sensors in modern buildings. This is opening up an unprecedented opportunity for implementing IPS by leveraging pre-existing infrastructure. Positioning can be a value-added secondary service of the infrastructure; while the Wi-Fi is in your home to primarily provide communication, it can also be leveraged to realize an IPS. Human activities alter Wi-Fi signal propagation, and these changes can be used to infer movement and position, identify and count people, interpret gestures. The floor can be repurposed to track the occupants’ footsteps, to identify that someone’s walking pattern has changed recently which alerts the family doctor about an early onset of a disease like Alzheimer or increased risk of suffering a fall. This can be achieved by monitoring the footstep induced vibration picked up by the building’s seismic sensors and the change in capacitive coupling between the body and the floor or powerline.  The lighting system, which is being envisioned to serve as high-speed data communication network, can also potentially act as the “GPS” for the vacuum cleaner and other robotic appliances in homes, help hospitals track its critical medical equipment, enable supermarkets to track the movement of their shopping trolleys and understand customer movement for better product placement. At Smart Lab we are developing IPS that are robust and real-world focused.