I've always been curious: where do the world's most impactful open-source developers actually live? Which cities produce the most stars? Is the "Silicon Valley dominates everything" narrative still true?
So I built DevGlobe — an interactive 3D globe that maps 26,000+ top open-source developers to their real-world locations, scored and ranked by their actual contributions.
How it works
Every developer is scored 0–100 using a composite algorithm across 6 dimensions:
| Dimension | Weight | Source |
|---|---|---|
| GitHub Stars | 25% | Total stars across all repos |
| GitHub Commits | 25% | Yearly commit activity |
| Repo Reach | 20% | Forks + watchers |
| SO Reputation | 15% | StackOverflow reputation |
| SO Engagement | 10% | Answer acceptance × count |
| Community | 5% | Followers + badges |
All dimensions are log-normalized to prevent one mega-repo from dominating the scores.
The data pipeline
The data comes from three sources, stitched together by a Node.js pipeline:
- GitHub GraphQL API — pulls top developers by follower count, then fetches their stars, commits, repos, and languages
- StackOverflow API — enriches profiles with reputation, answer count, and badges
- Geocoding — converts free-text locations ("SF", "Bangalore, India", "🇧🇷") into lat/lng coordinates
The final dataset is stored in Azure Cosmos DB with vector embeddings, enabling semantic search.
AI-powered search
This is the part I'm most proud of. You can type natural language queries like:
- "Python developer working on AI and deep learning"
- "Full stack JavaScript developer in London"
- "Linux kernel contributors"
It uses Azure OpenAI embeddings + Cosmos DB vector search to find semantically relevant developers — not just keyword matching.
The search supports three modes:
- Text — fast client-side filtering by name, username, location
- Vector — semantic similarity via embeddings
- Hybrid — combines both using Reciprocal Rank Fusion (RRF)
Interesting patterns I found
After staring at this globe for way too long, here's what stood out:
- The US West Coast and Western Europe dominate, but clusters in India, China, and Brazil are growing rapidly
- C and JavaScript developers are the most geographically distributed
- The top 100 developers live in just ~12 cities — San Francisco, London, Beijing, Bangalore, Berlin, Tokyo, Shanghai, New York, Singapore, Sydney, Toronto, Portland
- StackOverflow reputation doesn't correlate strongly with GitHub stars — the top GitHub developers rarely answer SO questions, and top SO contributors often have modest repos
- Eastern Europe punches above its weight — Ukraine, Poland, and Czech Republic have disproportionately high scores per capita
Tech stack
| Layer | Technology |
|---|---|
| Frontend | React 19, Three.js (react-globe.gl), Next.js 15 |
| Search | Azure Cosmos DB (vector + hybrid search) |
| Embeddings | Azure OpenAI (text-embedding-3-small) |
| API | Next.js API Routes |
| Hosting | Vercel |
| Data Pipeline | Node.js (GitHub GraphQL, StackOverflow API, geocoding) |
Try it yourself
Live demo: devglobe.vercel.app
GitHub: github.com/sajeetharan/devglobe
The project runs locally with zero configuration — no API keys needed. Just:
git clone https://github.com/sajeetharan/devglobe.git
cd devglobe
npm install
npm run dev
It ships with sample data (20 developers) so you can explore the UI immediately. For the full database experience, there's a one-command script to seed the Cosmos DB Emulator locally.
What's next
- Country-specific landing pages (SEO for "top developers in X")
- Embeddable profile badges for GitHub READMEs
- Time-series view showing how the developer landscape shifts over years
- More data sources (GitLab, npm downloads, conference talks)
Contributing
The project is fully open source and contributions are welcome. The CONTRIBUTING.md has all the details. Whether it's improving the scoring algorithm, adding data sources, or fixing UI bugs — PRs are appreciated.
If you find it useful, a ⭐ on the repo helps a lot!
Built by @sajeetharan
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