Development Workload Parameters
Interactive
Monthly Target Pull Requests
45 PRs / month
Average Task Complexity
Devin First-Pass Success Rate
75% (25% Retry Loops)
Senior Engineer Review Rate
$95 / hour
Senior Review Minutes per PR
25 minutes
Human Freelancer Hourly Rate
$55 / hour
Freelancer Hours per Merged PR
3.5 hours
ECONOMIC ADVANTAGE: Devin Delivers 71.4% Cost Reduction! At 45 medium PRs/month, hiring freelance developers costs $8,662/mo ($192/PR). Devin costs $2,480/mo total ($55/PR loaded with human review), saving $6,182/month.
Devin Blended Cost / PR
$55.12
ACU compute + Senior human review
Freelancer Cost / PR
$192.50
3.5 hrs @ $55/hr contract labor
Net Monthly Savings
$6,182
71.4% cost savings
Devin Monthly Invoice
$500
235 / 250 ACUs consumed
Loaded Cost Comparison per Merged Pull Request
BLENDED UNIT ECONOMICS
Pull Request Cost Ledger
Audit Table
| Cost Component | Cognition Devin | Contract Freelancer | Claude Code CLI (Local) |
|---|---|---|---|
| Compute / Execution Fee | $15.54 (ACU) | $0.00 | $1.45 (Tokens) |
| Base Subscription Amortization | $11.11 / PR | $0.00 | $0.00 (Pay-as-you-go) |
| Human Review Labor | $39.58 (25 mins) | $192.50 (3.5 hrs) | $39.58 (25 mins) |
| TOTAL LOADED COST / MERGED PR | $55.12 | $192.50 | $41.03 |
AI Pull Request Verification Harness
Copyable Code
# .github/workflows/ai-pr-guard.yml - Strict automated gatekeeper for Devin & Claude PRs
name: AI Pull Request Guard
on:
pull_request:
types: [opened, synchronize]
jobs:
validate-ai-pr:
runs-on: ubuntu-latest
steps:
- name: Checkout Code
uses: actions/checkout@v4
- name: Setup Node & Python
uses: actions/setup-node@v4
with:
node-version: 20
- name: Run Lint and Type Check
run: |
npm ci
npm run typecheck
npm run lint
- name: Run Full Test Suite with Coverage
run: |
npm test -- --coverage --ci
- name: Enforce Test Coverage Regression Floor
run: |
python3 -c "
import json
cov = json.load(open('coverage/coverage-summary.json'))['total']['lines']['pct']
if cov < 85.0:
print(f'CRITICAL: Coverage dropped to {cov}%. Rejecting AI PR.')
exit(1)
print(f'Coverage check passed: {cov}%')
"# evaluate_devin_pr.py - Measure ACU efficiency and merge success rate
import requests
import os
DEVIN_API_KEY = os.environ.get("DEVIN_API_KEY")
def trigger_devin_task(prompt, repo_url):
headers = {
"Authorization": f"Bearer {DEVIN_API_KEY}",
"Content-Type": "application/json"
}
payload = {
"prompt": prompt,
"repo": repo_url,
"max_acus": 6, # Cap ACU spending to avoid loops
"require_test_pass": True
}
response = requests.post("https://api.devin.ai/v1/sessions", json=payload, headers=headers)
session = response.json()
print(f"[Devin Session Created] ID: {session['session_id']}")
return session
if __name__ == "__main__":
task = "Fix authentication cookie expiration bug in src/auth/session.ts and write 3 unit tests"
trigger_devin_task(task, "github.com/my-org/core-saas")#!/bin/bash
# run_claude_code_task.sh - Low-cost ($0.80) terminal execution alternative to Devin
export ANTHROPIC_API_KEY="$ANTHROPIC_API_KEY"
echo "=== Running Claude Code Autonomous Task ==="
claude --print "Fix auth cookie expiration in src/auth/session.ts, verify with npm test, and create a git commit" --dangerously-skip-permissions
git status
git log -1 --stat{
"$schema": "http://json-schema.org/draft-07/schema#",
"title": "AIPullRequestAccounting",
"type": "object",
"properties": {
"pr_number": { "type": "integer" },
"agent_provider": { "type": "string", "enum": ["devin", "cursor", "claude_code"] },
"acus_consumed": { "type": "number" },
"token_cost_usd": { "type": "number" },
"review_time_minutes": { "type": "integer" },
"senior_hourly_rate": { "type": "number" },
"first_pass_merge": { "type": "boolean" },
"total_loaded_cost_usd": { "type": "number" }
},
"required": ["pr_number", "agent_provider", "total_loaded_cost_usd"]
}