---
title: "How the Creator of Claude Code Ships 40,000 Lines of AI-Written Code Per Month"
date: 2026-01-17T19:00:00.000Z
description: "Boris Cherny, creator of Claude Code at Anthropic, shared his workflow for running 10+ AI agents in parallel. Here's how he shipped 259 PRs in 30 days—and what we can learn from it."
tags: ["claude-code", "ai-coding", "developer-workflow", "anthropic", "vibe-coding", "ai-agents", "productivity", "software-development"]
tokens: 1685
content-signal: search=yes, ai-input=yes, ai-train=no
---
## TL;DR - Key Takeaways
1. **Run 5-10 Claude agents in parallel** across terminal and browser
2. **Use Opus 4.5 with thinking mode** - slower but requires less steering
3. **Maintain a CLAUDE.md file** as shared memory for mistakes and conventions
4. **Plan first, execute second** - don't let AI start coding until the plan is solid
5. **Verification is non-negotiable** - every change must be tested
---
## The Thread That Broke Developer Twitter
Boris Cherny ([@bcherny](https://x.com/bcherny)), the creator of Claude Code at Anthropic, recently shared his complete workflow for AI-assisted development. The numbers are staggering:
In a 30-day period, Boris reported:
- **259 Pull Requests**
- **497 Commits**
- **~40,000 lines added**
- **~38,000 lines removed**
All written by Claude Code under his direction.
---
## The 10-Step Workflow
Let me break down each element of Boris's workflow and explain why it works.
### 1. Parallel Agent Instances
Boris runs **5-10 Claude agents simultaneously**:
| Setup | Purpose |
|-------|---------|
| 5 Terminal instances | Each with separate git checkout |
| 5-10 Browser sessions | Via claude.ai/code |
| Mobile sessions | Start on phone, resume on desktop |
**Why this works**: Different agents handle different concerns—one refactors, one writes tests, one updates docs. No merge conflicts because each has its own branch.
**How to implement**:
```bash
# Create multiple working directories
git worktree add ../project-refactor feature/refactor
git worktree add ../project-tests feature/tests
git worktree add ../project-docs feature/docs
# Run Claude Code in each
cd ../project-refactor && claude
cd ../project-tests && claude
cd ../project-docs && claude
```
---
### 2. Model Choice: Opus 4.5 with Thinking
Boris exclusively uses **Opus 4.5** (not Sonnet) with **thinking mode always on**.
| Model | Speed | Accuracy | Steering Needed |
|-------|-------|----------|-----------------|
| Sonnet | Fast | Good | More corrections |
| **Opus 4.5** | Slower | Better | Less steering |
**The insight**: Raw speed is a trap. A faster model that needs constant correction is slower than a deliberate model that gets it right the first time.
---
### 3. The CLAUDE.md File
The **CLAUDE.md file** is the secret weapon. It's a living document of:
- Mistakes Claude should avoid
- Architectural preferences
- Naming conventions
- Project-specific patterns
**Example CLAUDE.md structure**:
```markdown
# CLAUDE.md - Project Guidelines
## Architecture
- Use functional components only
- State management via Zustand, not Redux
- All API calls go through /lib/api.ts
## Common Mistakes to Avoid
- Don't use `any` type in TypeScript
- Always handle loading and error states
- Never commit console.log statements
## Naming Conventions
- Components: PascalCase
- Hooks: useCamelCase
- Utils: camelCase
## Testing
- Every component needs a test file
- Use React Testing Library, not Enzyme
```
---
### 4. PR Reviews Update CLAUDE.md
The team has **automated learning** built into their PR process:
```mermaid
flowchart LR
A[PR Created] --> B[Human Review]
B --> C{Issue Found?}
C -->|Yes| D[Tag @claude]
D --> E[GitHub Action]
E --> F[Update CLAUDE.md]
F --> G[Future agents learn]
C -->|No| H[Merge PR]
```
**This is organizational memory at scale**. Every mistake becomes a lesson for all future Claude sessions.
---
### 5. Plan Mode First
The workflow is **Plan → Refine → Execute**:
| Phase | Mode | Human Involvement |
|-------|------|-------------------|
| 1. Plan | Plan mode | High - back-and-forth |
| 2. Refine | Plan mode | Medium - clarifications |
| 3. Execute | Auto-accept | Low - monitoring |
**Why this matters**: Fixing a bad plan is cheap. Fixing bad code from a bad plan is expensive.
---
### 6. Slash Commands for Automation
**Slash commands** turn common workflows into one-liners:
```
.claude/commands/
├── commit-push-pr.md
├── run-tests.md
├── format-all.md
├── deploy-staging.md
└── update-deps.md
```
**Example: commit-push-pr.md**
```markdown
# Commit, Push, and Create PR
1. Stage all changes
2. Generate commit message from diff
3. Push to current branch
4. Create PR with description from commits
5. Request review from team
```
---
### 7. Hooks for Continuous Automation
**Hooks** trigger automation at specific points:
| Hook Type | Trigger | Example Use |
|-----------|---------|-------------|
| PostToolUse | After any tool runs | Auto-format code |
| PreToolUse | Before tool runs | Validate safety |
| Stop | When Claude stops | Run test suite |
---
### 8. Pre-Approved Permissions
**Example .claude/settings.json**:
```json
{
"permissions": {
"allow": [
"npm install",
"npm run test",
"npm run build",
"git add",
"git commit",
"git push",
"eslint --fix"
],
"deny": [
"rm -rf",
"sudo",
"npm publish"
]
}
}
```
---
### 9. Tool Integrations
Claude Code integrates with:
| Tool | Purpose |
|------|---------|
| **Slack** | Communication, status updates |
| **BigQuery** | Query production data |
| **Sentry** | Read error logs |
| **GitHub** | PR management |
| **Internal APIs** | Custom business logic |
---
### 10. Verification is #1
**Verification is non-negotiable**:
```mermaid
flowchart TB
A[Claude writes code] --> B[Unit tests pass?]
B -->|No| A
B -->|Yes| C[Integration tests?]
C -->|No| A
C -->|Yes| D[Browser verification?]
D -->|No| A
D -->|Yes| E[Ready for review]
```
---
## What Could Be Improved
While Boris's workflow is impressive, there are areas for enhancement:
### 1. Better Agent Coordination
Currently, parallel agents are isolated. Future improvements could include:
- **Shared context** between agents
- **Automatic task delegation** based on agent specialization
- **Conflict detection** before branches diverge too far
### 2. Learning Across Projects
CLAUDE.md is per-repo. What if learnings could be:
- **Shared across similar projects** (all React apps, all Python services)
- **Company-wide mistake databases**
- **Industry-wide best practice libraries**
### 3. Smarter Verification Pipelines
Current verification is manual to set up. Improvements:
- **Auto-detect what needs testing** based on changes
- **Visual regression testing** without configuration
- **Performance impact analysis** before merge
### 4. Better Rollback and Recovery
When an agent goes wrong:
- **Automatic checkpoint** before major changes
- **One-click rollback** to last known good state
- **Blame-aware debugging** showing which agent introduced bugs
### 5. Cost Optimization
Running 10 Opus 4.5 instances is expensive. Potential improvements:
- **Dynamic model selection** based on task complexity
- **Agent hibernation** when idle
- **Batch processing** for similar tasks
---
## How to Apply This Today
You don't need to be at Anthropic to use these techniques:
### Starter Setup
1. **Create a CLAUDE.md** in your repo
2. **Set up git worktrees** for parallel work
3. **Create your first slash command**
4. **Configure permissions** in settings
### Minimum Viable Workflow
```bash
# 1. Create CLAUDE.md
echo "# Project Guidelines\n\n## Rules\n- Use TypeScript\n- Write tests" > CLAUDE.md
# 2. Create commands directory
mkdir -p .claude/commands
# 3. Create a simple command
echo "Stage, commit with conventional message, push, create PR" > .claude/commands/ship.md
# 4. Start with plan mode
claude --plan "Add user authentication feature"
```
---
## Conclusion
Boris Cherny's workflow represents the cutting edge of AI-assisted development. The key insights:
1. **Quantity enables quality** - More agents mean more parallel progress
2. **Memory matters** - CLAUDE.md turns mistakes into organizational knowledge
3. **Plan before execute** - Upfront thinking saves downstream debugging
4. **Verify everything** - AI-written code needs the same scrutiny as human code
5. **Automate the repetitive** - Slash commands and hooks free you for high-value work
The future isn't AI replacing developers—it's developers orchestrating fleets of AI agents, each specialized, each learning, each contributing to a velocity previously impossible.
---
**Sources:**
- [Boris Cherny's Twitter Thread](https://twitter.com/bcherny/status/2007179832300581177)
- [How Boris Uses Claude Code](https://howborisusesclaudecode.com/)
- [Reddit Discussion on Claude Code Stats](https://www.reddit.com/r/ClaudeAI/comments/1px44q0/claude_code_creator_boris_cherny_reports_a_full/)
---
**Last Updated:** January 2026
**Questions?** Connect on [LinkedIn](https://www.linkedin.com/in/agrawal-sumit/) or [GitHub](https://github.com/tech-sumit).