Sentinel is a distributed uptime monitoring platform featuring a decoupled NestJS REST API and an independent Go worker for concurrent endpoint verification, designed for production resilience and deployed on AWS.
┌────────────────────────┐
│ Browser / React Client │
└───────────┬────────────┘
│ HTTPS
▼
┌─────────────┴────────────────┐
│ Caddy reverse proxy │
│ (production edge) │
└──┬────────────────────┬──────┘
│ other paths │ /api/* (direct)
▼ ▼
┌─────────────┐ ┌───────────────────┐
│ Nginx (UI) │ │ NestJS REST API │
│ static SPA │ │ (JWT auth & CRUD) │
└─────────────┘ └─────────┬─────────┘
│ Prisma queries
▼
┌───────────────────┐
│ PostgreSQL 17 │
│ (shared schema) │
└─────────▲─────────┘
│ pgx: due monitors
│ & check results
┌─────────┴─────────┐
│ Go poller worker │
│ (checker registry)│
└─────────┬─────────┘
│ SSRF-filtered
│ HTTP/S requests
▼
┌───────────────────┐
│ Configured HTTP / │
│ HTTPS targets │
└───────────────────┘
-Concurrent Go worker: goroutines with channel-based bounded concurrency and pgxpool, load-tested locally with 5,000 monitors
-Network security & SSRF defense: custom DNS resolution with socket pinning against DNS rebinding, private IP blocking, and rate limiting
-Cloud deployment & CI/CD: AWS EC2, Docker Compose, Caddy reverse proxy with automatic HTTPS, and GitHub Actions with 250+ automated tests
TypeScript · NestJS · Go · PostgreSQL · React · Docker · AWS EC2