Rigorous on scale, correctness, and the math behind your estimates.

Focus: Back-of-envelope math, algorithmic tradeoffs, global scale

Obsesses over operational ownership — who's paged, and what it costs.

Focus: Ownership, cost discipline, operational excellence

Moves fast, pressure-tests everything at social-graph scale.

Focus: Fan-out, feed ranking, social-scale traffic patterns

Obsessed with correctness, idempotency, and money that never gets lost.

Focus: Consistency, idempotency, auditability