# Project Nebula — Technical Overview (Sample RAG Document)

## Architecture

Project Nebula is a microservices-based platform deployed on Kubernetes. Services
communicate via gRPC with REST gateways for external clients. The primary data store
is PostgreSQL 15 with Redis for caching and session management.

## Key Services

- **auth-service:** Handles user authentication (OAuth 2.0 + JWT). Endpoints: /login,
  /refresh, /logout, /validate.
- **payment-service:** Processes payments via Stripe integration. Supports one-time
  payments and subscriptions. Idempotency keys required for all POST requests.
- **notification-service:** Sends email (SendGrid), SMS (Twilio), and push notifications
  (Firebase). Uses a priority queue: critical (immediate), normal (batched every 5 min).

## Deployment

Deployments use ArgoCD with a GitOps workflow. Staging deployments are automatic on merge
to main. Production deployments require manual approval in the ArgoCD dashboard.
Rollbacks are triggered automatically if error rate exceeds 5% for more than 2 minutes.

## On-Call Rotation

On-call rotation is weekly, starting Monday at 9 AM ET. Primary on-call carries the
PagerDuty phone. Secondary on-call is escalation path. Runbooks are in the
internal wiki at wiki.internal.widgetcorp.com/on-call.