During the COVID-19 pandemic, I contributed to several projects and tech consortiums aimed at addressing critical public health challenges. One of the key areas I focused on was contact tracing. Since COVID-19 spreads through airborne particles and droplets, tracing the movements of exposed individuals became crucial to control transmission. Bluetooth-enabled phones were identified as a promising tool for this, as the signal strength between two devices typically correlates with their distance. However, the relationship between signal strength and distance is noisy, influenced by factors such as the angle between devices and phone manufacturing differences. To address these challenges, I collaborated with researchers at MIT PathCheck to develop an AI model capable of predicting close proximity between devices, considering Bluetooth signals and other confounding factors. Our model placed third in a competition hosted by the National Institute of Standards and Technology (NIST), and we coauthored a paper detailing the model, which was accepted at the Machine Learning for Mobile Health Workshop at NeurIPS. The model was implemented in the PathCheck app, which has been adopted by governments in Minnesota, Hawaii, Guam, Puerto Rico, Teton County, Wyoming, and Cyprus. link to code