🧬 Commit DNA – Developer Coding Style Analyzer

Decode any developer's coding DNA from their Git history. Analyzes public GitHub repos to reveal coding patterns, work habits, and burnout risk — all computed live from real commit data.

📌 Table of Contents

• What is Commit DNA?

• How It Works

• Metrics Explained

• Burnout Formula

• Example Walkthrough

• Tech Stack & Architecture

• How to Run

• Roadmap

🧠 What is Commit DNA?

Every Git commit is a timestamped record: who wrote it, when, what they described, and which lines changed. Commit DNA reads an entire repo's history and generates a visual dashboard answering:

QuestionMetricWorks late at night? Night Ratio — % of commits between 10 PM – 5 AM

Works on weekends? Weekend Ratio — % of commits on Sat/Sun

Frequent bug fixes? Bug Rate — % of commits mentioning "fix", "bug", etc.

Invests in code quality? Refactor Rate — % of commits about cleanup/optimization

At risk of burnout? Burnout Score — weighted formula combining all above

Think of it as a health checkup for coding habits — no hardcoded data, everything is computed live from actual Git history.

🔄 How It Works (Step by Step)

User enters GitHub URL → Validate → Clone repo → Extract git log → Parse commits → Calculate metrics → Burnout score → Display dashboard → Cleanup

1️⃣ Validation

Frontend checks: valid URL? Points to github.com? Has user/repo path?

2️⃣ Clone

Backend clones the repo into a temp folder with a unique UUID (supports concurrent users).

3️⃣ Extract Git Log

Runs: git log --numstat --pretty=format:"commit_separator|AuthorName|Date|Message"

Produces raw data like:

commit_separator|John Doe|Mon Mar 1 23:30:00 2026|fix: resolve login bug
5       2       src/auth.js

4️⃣ Parse

Each commit becomes a structured object with author, date, message, additions, deletions.

5️⃣ Calculate

Every commit is checked:

• Night? → Hour between 22:00–04:59

• Weekend? → Saturday or Sunday

• Bug fix? → Message contains: fix, bug, patch, hotfix, resolve

• Refactor? → Message contains: refactor, cleanup, optimize, clean, restructure, perf

6️⃣ Score & Display

Ratios calculated → Burnout formula applied → Charts rendered → Temp repo deleted.

📈 All Metrics Explained

🌙 Night Ratio

Night Ratio = Commits between 10 PM – 5 AM ÷ Total Commits

| 0–10% ✅ Normal | 10–25% ⚠️ Moderate | 25%+ 🔴 Frequently coding past midnight |

📅 Weekend Ratio

Weekend Ratio = Saturday + Sunday Commits ÷ Total Commits

| 0–10% ✅ Healthy boundary | 10–25% ⚠️ Some weekend work | 25%+ 🔴 Regular weekend coding |

🐛 Bug Rate

Bug Rate = Bug-fix Commits ÷ Total Commits

Keywords: fix · bug · patch · hotfix · resolve

| 0–5% ✅ Low | 5–15% ⚠️ Normal | 15%+ 🔴 May need better testing |

🔧 Refactor Rate

Refactor Rate = Refactor Commits ÷ Total Commits

Keywords: refactor · cleanup · optimize · clean · restructure · perf

| 0–2% ⚠️ Low investment | 2–10% ✅ Healthy | 10%+ ⚠️ Architecture may be unstable |

📊 Commit Spike

Commit Spike = (Max Commits in One Day ÷ Average per Day) − 1

Value of 0 = steady pace. Value of 4 = busiest day had 5× more commits than average.

🔥 The Burnout Formula

Burnout Score = 0.4 × Night Ratio
             + 0.3 × Weekend Ratio
             + 0.2 × Commit Spike (capped at 1.0)
             + 0.1 × Bug Rate

Why These Weights?

FactorWeightReasoningNight Ratio40%#1 indicator of overwork; correlates with fatigue and reduced code qualityWeekend Ratio30%Erodes recovery time; second strongest burnout signalCommit Spike20%Burst-then-rest patterns suggest deadline pressureBug Rate10%Can be a symptom of fatigue, but has many other causes

Status Thresholds

ScoreStatusMeaning0.00 – 0.24🟢 HealthySustainable patterns, normal hours0.25 – 0.49🟡 MediumSome concerning signals, worth monitoring0.50 – 1.00🔴 OverloadedMultiple burnout indicators elevated

Worked Example

Night Ratio = 0.30, Weekend Ratio = 0.20, Spike = 0.80, Bug Rate = 0.12

Score = (0.4 × 0.30) + (0.3 × 0.20) + (0.2 × 0.80) + (0.1 × 0.12)
      = 0.12 + 0.06 + 0.16 + 0.012
      = 0.352 → 🟡 Medium

🎯 Example Walkthrough

Input: https://github.com/expressjs/express (~3,800 commits)

Output:

{
  "developerName": "TJ Holowaychuk",
  "totalCommits": 3847,
  "nightRatio": 22.5,
  "weekendRatio": 15.3,
  "bugRate": 8.7,
  "refactorRate": 5.2,
  "burnoutScore": 0.48,
  "burnoutStatus": "Medium"
}

Dashboard shows: Profile card → Bar chart (night vs day) → Doughnut (bugs vs refactors) → Gauge (burnout score)

🏗 Tech Stack & Architecture

LayerTechnologiesFrontendHTML5, CSS3 (dark theme), Vanilla JS, Chart.jsBackendNode.js, Express.js, simple-git, day.js

┌──────────── FRONTEND ────────────┐
│  index.html → dashboard.html     │
│  css/style.css  js/api.js        │
│  js/charts.js   js/dashboard.js  │
└──────────┬───────────────────────┘
           │ POST /analyze
           ▼
┌──────────── BACKEND (Express) ───┐
│  gitService → parserService      │
│  metricsService → burnoutService │
│  → JSON response with metrics    │
└──────────────────────────────────┘

🚀 How to Run

# Install & start
cd backend && npm install && npm run dev

# Open commit-dna-lkc9.vercel.app

Prerequisites: Node.js v16+, Git installed.

🗺 Future Roadmap

PhaseFeatureStatus1Public repo analysis + dashboard + burnout scoring ✅ Done

Private repos (GitHub OAuth), multi-dev comparison 🔜 Planned

Team analytics, Slack alerts, AI recommendations 💡 Idea