What problem does it solve? Engineers often write logic before settling core data structures, leading to premature abstractions, late-stage rewrites, and concurrency bugs. This Skill applies foundational thinking principles so structural decisions are made first and downstream code becomes obvious. ## Core Features & Use Cases - Data Structures First: Prompts definition of core types early, tracing access patterns, and choosing structures that match dominant code paths. - Scaffold Sequencing: Orders work so CI, linting, test infrastructure, and shared types land before features, keeping commits small and single-purpose. - Concurrency Corollary: Forces the question of what happens when another actor modifies shared state, isolating state when the answer is not nothing. - Use Case: Before implementing a new service module, apply this Skill to decide the core data model, sequence test infrastructure ahead of features, and remove dead code before scaffolding. ## Quick Start Ask the agent to apply foundational thinking to plan the data structures and work sequence for the feature you are about to implement.