A role between a full engineering manager and a pure individual contributor: a senior engineer who also runs a small team, typically staffed on ambitious side bets rather than the core roadmap. It lets a company attempt historically "too hard" projects without committing a full specialist pod (Pod HR Ratio (Designer/PM per Six Engineers)) to an unproven idea.
Used inside Whatnot's Explore/Exploit Dual Portfolio Management approach: the core stays staffed with full teams, while EM-light-led pods run the exploratory edge.