# Yaduraj Singh — Full-stack engineer · AI/ML builder

> Ships production-grade systems solo — firmware on ESP32, scalable SaaS, iOS apps. Three live products with real users before 21.

Yaduraj Singh is a 20-year-old full-stack engineer · ai/ml builder based in Dehradun · Greater Noida, India.

## Highlights

- Self-hosted Linux infrastructure — Nginx, SSL, PM2, systemd. Not just Vercel deploys.
- Manual WebRTC: full ICE/STUN/TURN + signalling layer. No third-party video SDK.
- Designed multi-tenancy, RBAC, caching, CI/CD for a hospital SaaS — solo, from a blank repo.
- Three live production applications with real users before age 21.
- Hackathon-winning hardware + AI system: ESP32-S3 + FastAPI + Flutter, team of two.
- AI/ML pipelines: handwriting synthesis, voice + LLM + TTS cognitive OS, wearable vitals monitoring.

## By the numbers

- **2,000+** users in production
- **08** shipped projects
- **03** hackathons won
- **04** self-hosted servers

## Now building

**Tollgate** (private beta) — Cost & usage observability for LLM APIs. Reverse proxy for OpenAI, Anthropic, and OpenAI-compatible providers — one base URL for per-feature cost, exact-match caching, budgets, and runaway-agent alerts.

- Point one base_url at Tollgate — OpenAI, Anthropic, xAI, OpenRouter, Gemini, and more. No SDK rewrite.
- Per-feature (tag) spend visibility, exact-match prompt caching, and hard budgets.
- Runaway-agent alerts & guards — stop burn before another overnight surprise bill.

## Projects

### Aarogya Setu

Multi-tenant hospital SaaS — OPD/IPD queues, EMR, appointments, billing, pharmacy, diagnostics. 6-tier RBAC.

- Category: SaaS · Self-hosted
- Stack: Next.js 14, TypeScript, Prisma, PostgreSQL, Redis, Docker
- Live: https://arogya.yaduraj.me

### MuhDikhai

Omegle-style anonymous video chat. Full WebRTC peer lifecycle built manually over Socket.io. Sub-2s pairing.

- Category: Real-time · WebRTC
- Stack: Node.js, TypeScript, WebRTC, Socket.io, PostgreSQL
- Live: https://batchit.yaduraj.me

### CineVerse

Social film tracking — watchlists, ratings, reviews, discovery feeds. TMDB API across 500k+ titles.

- Category: Social · SSR
- Stack: Next.js, Firebase, TMDB API, Nginx, PM2
- Live: https://cine.yaduraj.me

### SecondMind / CortX

Cognitive OS on ESP32-S3 Sense. Voice → faster-whisper → local LLM → Coqui TTS. VAD firmware, Opus compression.

- Category: Hackathon Winner
- Stack: ESP32-S3, FastAPI, Flutter, Neo4j, Qdrant
- Live: https://cortx.yaduraj.me

### GBU Timetable

Official iOS app for GBU students. Live home-screen widgets via WidgetKit. Real-time schedule updates.

- Category: iOS · App Store
- Stack: SwiftUI, Combine, WidgetKit
- Live: https://apps.apple.com

### Maakosh

Maternal & neonatal health iOS app. Wearable sensor integration (MAX30100, EMG) for real-time vitals. Role-based.

- Category: Hackathon Winner
- Stack: Swift, Firebase, ThingSpeak

### Bolonyay

Multilingual legal aid iOS app — petitioners with regional advocates. Voice-assisted forms, automated PDF reports.

- Category: iOS · Legal Aid
- Stack: Swift, Firestore, PDFKit, STT

## Stack

- **Full-stack web:** Next.js 14, React 18, TypeScript, Node.js, Express, tRPC, Tailwind, shadcn/ui
- **Mobile / iOS:** Swift, SwiftUI, UIKit, Combine, WidgetKit, AVFoundation, Flutter, Dart
- **Real-time & networking:** WebRTC, Socket.io, REST, GraphQL, Cloudflare Tunnels
- **AI / ML:** faster-whisper, LM Studio, Coqui TTS, Qdrant, Neo4j, Celery/Redis, xlm-roberta, spaCy, Ollama
- **Embedded / hardware:** ESP32-S3, FreeRTOS, I2S, BLE, Opus, PSRAM, C/C++
- **Databases:** PostgreSQL, Prisma, Firebase, Redis, MongoDB, MySQL
- **DevOps / infra:** Docker, Compose, GitHub Actions, Nginx, PM2, Certbot, systemd, Vercel, SSH

## Contact

- Email: yadurajsingham@gmail.com
- GitHub: https://github.com/YadurajManu
- LinkedIn: https://www.linkedin.com/in/yadurajenc
- Résumé: https://www.yaduraj.me/Resume_Web.pdf