Massive macromolecular complexes are essential in many cellular processes, including transcription, translation, splicing, nuclear import/export, metabolism, and degradation. The assembly of these molecular machines is extremely complex, requiring the production and precise binding of dozens of components and yet healthy cells accomplish this task rapidly and efficiently. For example, bacteria assemble ~100,000 ribosomes/h, with each ribosome requiring the coordinated synthesis, RNA processing, and folding of three large ribosomal RNAs, and the translation, folding, modification, and binding of ~50 ribosomal proteins. Notably, errors in these assembly and disassembly processes dysregulate cellular homeostasis and have been linked to a variety of diseases. The Davis lab is actively working to uncover how these complex molecular machines are assembled, disassembled, and degraded, and to learn how environmental stress, mutations, disease, and aging alter the fidelity of these processes. We complement in vitro biochemical experiments with a variety of computationally intense approaches, including single particle cryo-electron microscopy and quantitative mass spectrometry. Ongoing projects in the lab are focused on autophagy, an essential protein and organelle degradation pathway, and assembly of the ribosome, which is required for translation in all cells.