Archivematica began in 2008 as a working hypothesis that assumed a comprehensive yet free digital preservation system could be created by matching existing open-source software tools against the OAIS functional model. Five years later the production release of the software is ready to go into production at several major North American archives and libraries, while the beta version is already widely-deployed worldwide. In the absence of a single major funding sponsor, the project management team worked as third-party contractors to several early-implementer institutions that shared the project’s architectural and open-source vision while needing to implement an effective and sustainable digital curation solution for the digital content entrusted to their care. From the outset, Archivematica’s system requirements were based on an ongoing dialogue within the digital curation community about the gaps between the standards and strategies that were held up as best practice and the ability for the average archivists and librarians to implement them. The iPres conference has proven to be a critical forum for advancing this dialogue and has included previous papers about the Archivematica micro-services architecture (2010) and its community-driven development approach (2012). This paper will provide a conclusion to these earlier papers by discussing the key architectural, digital curation and sustainability challenges that the Archivematica project has addressed as it emerged from a working prototype to a full-featured digital preservation system. This includes system scalability, customization, digital repository interfaces, format policy implementation, and a business plan that stays true to the ideals of the free software community.