During the COVID-19 crisis, the Chilean Ministries of Health and Sciences partnered with the Instituto Sistemas Complejos de Ingeniería (ISCI) and telecom company Entel to develop innovative methodologies and tools that placed O.R. and analytics at the forefront of the battle against the pandemic. These innovations have been used in key decisions aspects that helped shape the strategy against the virus, including tools that shed light on the actual effects of lockdowns in different municipalities and over time; helped allocate limited intensive care capacity; allowed multiplying the testing capacity; provided on-the-ground strategies for active search of asymptomatic cases based on anonymized mobility data; and implemented a nationwide serology surveillance program that greatly influenced Chile’s decision regarding booster doses and provided information to the world.