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)

Works in main branch OR worktree (no preference)

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

    IMPORTANT: Create TDD Compliance Certification for each function you implement
    (format specified in test-driven-development skill). Include this in your report.

    Work from: [directory]

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

Subagent reports back with summary of work.

3. Review Subagent's Work

Verify subagent provided TDD Compliance Certification:

• If certification missing or incomplete: Request it before proceeding to code review
• Certification must have entry for each new function

Dispatch code-reviewer subagent:

Task tool (wrangler:code-reviewer):
  Use template at requesting-code-review/code-reviewer.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 code-reviewer:

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

7. Complete Development

After final review passes:

• Announce: "I'm using the finishing-a-development-branch skill to complete this work."
• REQUIRED SUB-SKILL: Use wrangler: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 code-reviewer]
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 code-reviewer]
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 code-reviewer]
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 code-reviewer template: requesting-code-review/code-reviewer.md