Thermoplastic composites are well established in both automotive and aerospace industries. In combination with other materials, they form a key pillar of function-integrated lightweight design, especially in high-volume production applications. The intrinsic and extrinsic joints characteristic of hybrid and mixed construction methods involving thermoplastic composites play a special role due to their material-related and often geometric discontinuities within the structure, and therefore require particular attention. This publication provides a concise overview of important developments in recent years in the context of intrinsic and extrinsic joining techniques. Based on a comprehensive review of the diverse literature on the subject, it also presents the authors' own research findings on the manufacturing, characterization, and design of joints. The focus is on technological specifics, resulting material structure phenomena, and modeling approaches. Building on this, novel methods for deformation and damage analysis of joints are introduced and discussed.