Zoom info: https://stanford.zoom.us/j/93661002627?pwd=NnFZekcxWHdzNGk0eHovRUFLb1lP… Passcode: 892854 The cosmic microwave background (CMB) provides a snapshot of the early universe and serves a backlight for the subsequent 13.8 billion years of cosmic evolution. Upcoming surveys of the millimeter sky, designed to measure the CMB, will address a host of cosmological and astrophysical questions, from probing primordial gravity waves to constraining sum of the neutrino masses to understanding galactic star formation. Cryogenic superconducting detectors have become photon-noise limited, such that improving the sensitivity of CMB measurements requires increasing the number of these detectors on the sky. Since thermal loading and wiring complexity scale with detector count, novel multiplexing technologies, in which multiple detectors are read out with a single amplification chain, have been developed for CMB experiments. The Simons Observatory (SO), an upcoming CMB experiment, will deploy densely packed detector modules that utilize a novel microwave SQUID multiplexing architecture. The unprecedented multiplexing factor achieved by SO was made possible by advancements in both warm and cold readout electronics. I will present on the design, assembly, and validation of the SO detector modules.