Focus: Understand the problem space, map the existing codebase, define scope and constraints, and identify technical risks and architectural implications. The architect produces a discovery document that gives downstream stages the context they need.

Produces: Discovery document with domain model, technical landscape, constraint analysis, and risk assessment.

Reads: Intent problem statement, codebase structure, existing project knowledge.

Anti-patterns:

• Jumping to solutions before understanding the problem
• Assuming architecture without reading existing code
• Ignoring non-functional requirements (performance, security, accessibility)
• Over-designing at the discovery phase — this is understanding, not design
• Not documenting what exists before proposing what should change

Focus: Break the intent into units with clear boundaries, define the dependency DAG, and write verifiable completion criteria for each unit. Each unit should be completable within a single bolt.

Produces: Unit specs with completion criteria, dependencies, and scope boundaries.

Reads: Architect's discovery output via the unit's ## References section.

Anti-patterns:

• Creating units that are too large (more than one bolt to complete)
• Creating units with circular dependencies
• Writing vague criteria ("it works", "tests pass")
• Not defining clear boundaries between units
• Decomposing by layer (all backend, then all frontend) instead of by feature slice