Sébastien Ferreira-Cerca Cellular Biochemistry of Microorganisms - Biochemistry III, Regensburg Center for Biochemistry, Institute of Biochemistry, Genetics and Microbiology, University of Regensburg – Germany. sebastien.ferreira-cerca-at-ur.de Ribosomes are universally conserved molecular machines ensuring the decoding of the genetic information carried within mRNA intermediates into proteins. Remarkably, the ribosome molecular constituents, the ribosomal RNAs and ribosomal proteins, assemble into structural and functional entities conserved across the different domains of life. In addition, some general principles of ribosomal protein assembly seem to apply across the tree of life. In contrast, the ribosome biogenesis factor counterparts facilitating the ribosomal subunit assembly process apparently diverge between bacteria and eukaryotes. Interestingly, several eukaryotic-like ribosome biogenesis factor protein signatures are present and conserved in most archaeal genomes, suggesting that some aspects of ribosome biogenesis in archaea may resemble its eukaryotic counterpart. However, how ribosomes are made in archaea remains poorly characterized. To better disentangle common and specific principles of ribosome biogenesis within and across the different domains of life, our work aims to systematically characterize the ribosome biogenesis pathway in archaea. I will present some of our recent methodological developments and functional insights shedding light on eukaryotic-like, archaeal-specific, and archaeal-divergent steps of ribosome biogenesis in archaea. Moreover, I will also discuss how our understanding of the archaeal ribosome assembly pathway across the tree of life can contribute to the emergence of unified conceptual frameworks on ribosome biogenesis and its evolutionary history.