ADR-0016: Pivot to Google Cloud Platform (GCP)

Reviewed on 2026-03-06.

This ADR is a historical demo-environment decision, not current production hosting truth. For current runtime and hosting truth, use:

docs/architecture/CURRENT_ARCHITECTURE.md

docs/handoff/CHECKPOINT.md

docs/operations/DEPLOYMENT_RUNBOOK.md

Date: 2026-01-10 Status: ACCEPTED (DEMO ONLY) Context: v0.6.3 Demo Deployment Supersedes: AWS hosting choice for the demo environment only.

1. Context

Original plans (Task-085) targeted AWS EKS/EC2. During Phase 10 demo preparation, a decision was made to deploy to GCP for the v60.1.1 demonstration environment.

2. Decision

We are pivoting the primary demo environment to Google Cloud Platform.
Production baseline (AWS Terraform/IaC) remains unchanged.

Backend/Frontend: Hosted on Cloud Run (Serverless, Auto-scaling).
Database/Cache: Hosted on Compute Engine (GCE) VM (Cost-effective for stateful services).
Orchestration: Docker Compose (VM internal) + Cloud Run revisions.

3. Rationale

Speed: Cloud Run allows near-instant deployment of containers without K8s management overhead (gcloud run deploy).
Cost: GCE e2-small instances are cheaper than persistent AWS EKS control planes for demo purposes.
Simplicity: Removes the need for complex VPC/Ingress Controller setup required for AWS EKS.

4. Consequences

Positive: Deployment time reduced from days to hours.
Negative:
- POSTGRES_SSL is currently disabled (internal VM traffic only).
- GCP IaC is demo-focused; AWS Terraform remains the production baseline.
Mitigation:
- For production: migrate DB to Cloud SQL (Managed) or enable VPC Connector + SSL on GCE.
- Keep AWS docs as primary; mark GCP demo as alternative profile.

5. Compliance

Auth: Currently DISABLED for demo (see SECURITY_DISCLAIMER_DEMO.md).
Network: Services sit behind Cloud Load Balancing (auto-HTTPS).

6. Approval

This ADR requires explicit GO before changing any production hosting baseline.