FOSS powers the digital world we live in, but ensuring the long-term sustainability of the software and community can be challenging. In this talk, we will explore sustainable open source from three key perspectives: community, financial, and engineering practices. All three perspectives — community, financial and engineering practices — are vital for long-term sustainability of free and open source software projects. Abby will share insights and case studies on how well-crafted processes in each area can create a strong foundation for future success. She will draw on her experience as a maintainer of key open science projects, as well as a mentor and supporter to over 700 open source projects in GitHub's Top Maintainer program, UNICEF Venture Funds, and Mozilla Open Leaders. She will also discuss practical strategies for building effective open-source ecosystems, and ways to ensure the longevity of projects. The audience will leave with a better understanding of the importance of investing in sustainable open source practices, with tangible strategies for creating and sustaining successful projects. Join us for an engaging discussion on how to build a strong foundation for the future of free and open source software!