The Primordial Inflation Explorer (PIXIE) is a proposed NASA-led mission designed to measure the polarization and intensity of the cosmic microwave background (CMB). PIXIE will answer key questions about the origin and evolution of the universe, from the period of inflation immediately after the Big Bang to the present day. While most other instruments designed for CMB measurements are imagers, PIXIE is a Fourier transform spectrometer (FTS). Its highly-symmetric design enables excellent control of systematic effects and its sensitivity and bandwidth allow us to distinguish cosmological signals from signals originating within our own Galaxy. This thesis introduces the PIXIE experiment and details two specific areas of PIXIE development supported by my dissertation work: modeling and mitigation of instrumental systematic effects and the development of PIXIE’s multimode bolometers. PIXIE’s raw instrumental systematic error terms are small, generally from hundreds of nK to a few μK. But these terms will still overwhelm our target cosmological signals; for example the predicted B-mode polarization signal of the CMB, whose detection would provide strong evidence for inflation, is expected to be < 100 nK. In this work, I analytically solve for the most important systematic error signals caused by non-idealities within the PIXIE FTS. I then show how they are mitigated to acceptable levels with simple corrective actions. PIXIE achieves background-limited sensitivity with just 4 detectors. They require a vastly different optimization from bolometers developed for focal-plane imagers. They must handle a large, near-constant optical bias (~ 120 pW) but still operate with sensitivity near the thermodynamic limit. They must have a large and mechanically robust absorbing area (30 times larger than the spider web bolometers that flew on Planck) that is sensitive to all optical frequencies of interest but is relatively insensitive to cosmic ray hits. I detail our efforts to overcome these challenges and discuss the cryogenic and environmental performance of PIXIE’s prototype bolometers. Advisors/Committee Members: Tucker, Gregory (Advisor), Dell'Antonio, Ian (Reader), Fixsen, Dale (Reader).