The WorldPop project aimed to produce grid-based population estimates through 2030, broken down by gender and age group. The overall project was led by Prof. Andy Tatem of the University of Southampton. Within this framework, the IAPG was responsible for developing an innovative spatial data management system to harmonize and coordinate population statistics based on subnational administrative and statistical units. The challenges involved ensuring consistency and modeling changes in spatial references so that the database is easy to use and sustainable over the long term. In terms of data, the 2020 census round (i.e., 2015 to 2024) was the main focus. The data from the data model developed at the IAPG was incorporated as input into the overall WorldPop model.