The biodiversity crisis is a global phenomenon, and measures to monitor, stop, and revert the impacts on species' extinction risk are urgently needed. Megadiverse countries, especially in the Global South, are responsible for managing and protecting Earth's biodiversity. Various initiatives have started to sequence reference-level genomes or perform large-scale species detection and monitoring through environmental DNA. Here, we outline the Genomics of the Brazilian Biodiversity (GBB) consortium that is contributing to public policies on the conservation and management of Brazilian species. We describe our unique public-private governance and lessons in setting up a genomic consortium in a megadiverse country of continental scale. We explore the challenges while sharing knowledge for similar initiatives in the Global South. Ultimately, we aim to encourage Brazilian institutions and other megadiverse countries to invest and participate in large-scale genomic initiatives, demonstrating their commitment to preserving and monitoring their exceptional natural heritage while contributing to global biodiversity conservation.