Groundwork is a structured development workflow plugin that guides you from product requirements through architecture, implementation, and validation. It provides 28 skills and 22 commands covering product design (EARS requirements), architecture decision-making, test-driven development, systematic debugging, and multi-agent validation. Features include worktree-isolated task execution, parallel adversarial debugging with agent swarms, 9-agent validation loops, spec synchronization, and monorepo support. Groundwork encodes development best practices into guided workflows so nothing gets skipped.