  The 15th European Conference on Computer Systems (EuroSys'20) was organized
as a virtual (online) conference on April 27-30, 2020. The main EuroSys'20
track took place April 28-30, 2020, preceded by five workshops (EdgeSys'20,
EuroDW'20, EuroSec'20, PaPoC'20, SPMA'20) on April 27, 2020. The decision to
hold a virtual (online) conference was taken in early April 2020, after
consultations with the EuroSys community and internal discussions about
potential options, eventually allowing about three weeks for the organization.
This paper describes the choices we made to organize EuroSys'20 as a virtual
(online) conference, the challenges we addressed, and the lessons learned.
