Today's modern aerospace systems utilize significant proportions of embedded computing hardware. The amount and complexity of this hardware and the embedded software that run on this hardware has increased significantly over the past decades in order to better sense the environments and control the aerospace systems to accomplish the missions the systems are developed to meet. This chapter explores the selection of computing hardware from architecture to integration. It documents how a computing hardware element is specified, how it is architected into multiple approaches, how one approach is selected as a baseline, how that baseline is designed, analyzed, prototyped, reviewed, and released to fabrication, and then brought up, integrated, and tested. The approach covers areas of concern from the smallest elements of computing hardware logic to systems of computing hardware, including any needed test equipment. The selection and integration of computing hardware documented in this chapter continues to increase in its importance and contribution to the success of today's and future aerospace missions.