Mental Models
Team Topologies
Four team types and three interaction modes for organizing around fast flow instead of org-chart inertia.
Team Topologies (Skelton & Pais) argues most team structures optimize for reporting lines, not the actual flow of work. I use it to check whether a team's shape matches what it's actually trying to ship — stream-aligned teams doing the work, platform teams removing friction, and clearly defined interaction modes instead of ad hoc hand-offs.