Subagent-Driven Development

Execute plan by dispatching fresh subagent per task, with code review after each.

Core principle: Fresh subagent per task + review between tasks = high quality, fast iteration

Overview

vs. Executing Plans (parallel session):

• Same session (no context switch)
• Fresh subagent per task (no context pollution)
• Code review after each task (catch issues early)
• Faster iteration (no human-in-loop between tasks)

When to use:

• Staying in this session
• Tasks are mostly independent
• Want continuous progress with quality gates

When NOT to use:

• Need to review plan first (use executing-plans)
• Tasks are tightly coupled (manual execution better)
• Plan needs revision (brainstorm first)

The Process

1. Load Plan

Read plan file, create TodoWrite with all tasks.

2. Execute Task with Subagent

For each task:

Dispatch fresh subagent:

Task tool (general-purpose):
  description: "Implement Task N: [task name]"
  prompt: |
    You are implementing Task N from [plan-file].

    Read that task carefully. Your job is to:
    1. Implement exactly what the task specifies
    2. Write tests (following TDD if task says to)
    3. Verify implementation works
    4. Commit your work
    5. Report back

    Work from: [directory]

    Report: What you implemented, what you tested, test results, files changed, any issues

Subagent reports back with summary of work.

3. Review Subagent's Work

Dispatch review subagent:

Use template at requesting-code-review/review.md

WHAT_WAS_IMPLEMENTED: [from subagent's report] PLAN_OR_REQUIREMENTS: Task N from [plan-file] BASE_SHA: [commit before task] HEAD_SHA: [current commit] DESCRIPTION: [task summary]

**Code reviewer returns:** Strengths, Issues (Critical/Important/Minor), Assessment

### 4. Apply Review Feedback

**If issues found:**

- Fix Critical issues immediately
- Fix Important issues before next task
- Note Minor issues

**Dispatch follow-up subagent if needed:**

"Fix issues from code review: [list issues]"

### 5. Mark Complete, Next Task

- Mark task as completed in TodoWrite
- Move to next task
- Repeat steps 2-5

### 6. Final Review

After all tasks complete, dispatch final review:

- Reviews entire implementation
- Checks all plan requirements met
- Validates overall architecture

### 7. Complete Development

After final review passes:

- Announce: "I'm using finishing-a-development-branch skill to complete this work."
- **REQUIRED SUB-SKILL:** Use skill({ name: "finishing-a-development-branch" })
- Follow that skill to verify tests, present options, execute choice

## Example Workflow

You: I'm using Subagent-Driven Development to execute this plan.

[Load plan, create TodoWrite]

Task 1: Hook installation script

[Dispatch implementation subagent] Subagent: Implemented install-hook with tests, 5/5 passing

[Get git SHAs, dispatch review] Reviewer: Strengths: Good test coverage. Issues: None. Ready.

[Mark Task 1 complete]

Task 2: Recovery modes

[Dispatch implementation subagent] Subagent: Added verify/repair, 8/8 tests passing

[Dispatch review] Reviewer: Strengths: Solid. Issues (Important): Missing progress reporting

[Dispatch fix subagent] Fix subagent: Added progress every 100 conversations

[Verify fix, mark Task 2 complete]

...

[After all tasks] [Dispatch final review] Final reviewer: All requirements met, ready to merge

Done!

## Advantages

**vs. Manual execution:**

- Subagents follow TDD naturally
- Fresh context per task (no confusion)
- Parallel-safe (subagents don't interfere)

**vs. Executing Plans:**

- Same session (no handoff)
- Continuous progress (no waiting)
- Review checkpoints automatic

**Cost:**

- More subagent invocations
- But catches issues early (cheaper than debugging later)

## Red Flags

**Never:**

- Skip code review between tasks
- Proceed with unfixed Critical issues
- Dispatch multiple implementation subagents in parallel (conflicts)
- Implement without reading plan task

**If subagent fails task:**

- Dispatch fix subagent with specific instructions
- Don't try to fix manually (context pollution)

## Integration

**Required workflow skills:**

- **writing-plans** - REQUIRED: Creates the plan that this skill executes
- **requesting-code-review** - REQUIRED: Review after each task (see Step 3)
- **finishing-a-development-branch** - REQUIRED: Complete development after all tasks (see Step 7)

**Subagents must use:**

- **test-driven-development** - Subagents follow TDD for each task

**Alternative workflow:**

- **executing-plans** - Use for parallel session instead of same-session execution

See review template: requesting-code-review/review.md