AUTHOR=Baquero Carlos, Casari Paolo, Fernandez Anta Antonio, García-García Amanda, Frey Davide, Garcia-Agundez Augusto, Georgiou Chryssis, Girault Benjamin, Ortega Antonio, Goessens Mathieu, Hernández-Roig Harold A., Nicolaou Nicolas, Stavrakis Efstathios, Ojo Oluwasegun, Roberts Julian C., Sanchez Ignacio TITLE=The CoronaSurveys System for COVID-19 Incidence Data Collection and Processing JOURNAL=Frontiers in Computer Science VOLUME=3 YEAR=2021 URL=https://www.frontiersin.org/articles/10.3389/fcomp.2021.641237 DOI=10.3389/fcomp.2021.641237 ISSN=2624-9898 ABSTRACT=CoronaSurveys is an ongoing interdisciplinary project developing a system to infer the incidence of COVID-19 around the world using anonymous open surveys. The surveys have been translated into 60 languages and are continuously collecting participant responses from any country in the world. The responses collected are pre-processed, organized, and stored in a version-controlled repository, which is publicly available to the scientific community. In addition, the CoronaSurveys team has devised several estimates computed on the basis of survey responses and other data, and makes them available on the project’s website in the form of tables, as well as interactive plots and maps. In this paper, we describe the computational system developed for the CoronaSurveys project. The system includes multiple components and processes, including the web survey, the mobile apps, the cleaning and aggregation process of the survey responses, the process of storage and publication of the data, the processing of the data and the computation of estimates, and the visualization of the results. In this paper we describe the system architecture and the major challenges we faced in designing and deploying it.