Since 2016, hobby metal-detecting is legal in Flanders (Belgium), although it was unofficially tolerated for many years before. However, research on metal-detected artefacts in Flanders is hindered by a low reporting rate. The MEDEA project aims to address this by encouraging detectorists to record their finds on an online platform. Finds experts are invited to enrich records with further information and thus instigate a rewarding feedback cycle. This paper discusses MEDEA’s ‘Human-Centred Design’ development process and the design choices underpinning the platform. MEDEA may be seen as an example of ‘Open Archaeology’ and related trends in digital humanities.