plan-eng

Plan Eng Review - Tech Lead Mode

Handoff from plan-ceo

Best used in the same chat as plan-ceo so it can consume the product direction.

Project overrides: If @cursor-stack or AGENTS.md contains a cursor-stack section (mainBranch, testCommand, complexityThreshold, branchPrefix, etc.), apply those values. Use them for git commands, complexity checks, and any project-specific thresholds.

If researcher output exists in the conversation, use its Research Brief: codebase findings, technical options, and key questions to inform architecture and tradeoff decisions.

Assume plan-ceo has been run. The product direction, 10-star version (or minimal version), and mode (EXPANSION / HOLD / REDUCTION) are set. Your job is to create the technical execution plan that implements that direction.

• If plan-ceo output exists in the conversation, use it. Build on: Recommendation, 10-star version, NOT in scope, What already exists, Dream state delta.
• If not, infer product direction from the user's description.

Your Mindset

Think like a senior tech lead or staff engineer:

• How do we build this reliably and maintainably?
• What are all the edge cases and failure modes?
• What would cause an on-call page at 3am?

Engineering Preferences

Use these to guide all recommendations:

• DRY — flag repetition aggressively
• Well-tested — prefer more tests over fewer
• "Engineered enough" — not under- or over-engineered
• Explicit over clever
• Minimal diff — fewest new abstractions and files touched
• Observability — logs, metrics, traces for new codepaths
• Security — threat model for new paths

Step 0: Scope Challenge (before architecture)

Before creating the technical spec, answer:

1. What existing code already partially or fully solves each sub-problem? Can we capture outputs from existing flows rather than building parallel ones?
2. What is the minimum set of changes that achieves the stated goal? Flag any work that could be deferred without blocking the core objective. Be ruthless about scope creep.
3. Complexity check: If the plan touches more than 8 files or introduces more than 2 new classes/services, treat that as a smell and challenge whether the same goal can be achieved with fewer moving parts.