---
id: e80e161a-4be4-428d-8590-267b9ab4cc7c
type: decision
title: "Object-handler CloudSQL silver layer architecture"
tags: [esb-monorepo, object-handler, architecture, cloudsql, decision]
importance: 0.8
confidence: 0.8
created: "2025-12-10T19:55:26.314546+00:00"
updated: "2026-03-04T01:48:02.005397+00:00"
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For object-handler silver layer (CloudSQL) output: Use Cloud SQL Python Connector + pg8000 driver (not SQLAlchemy). Connection method chosen because: (1) Works in Docker locally AND Cloud Functions, (2) IAM auth eliminates password management, (3) No VPC connector needed. Postgres functions handle upsert logic, so raw SQL calls are sufficient - SQLAlchemy would be overkill. Data flow: raw_data stripped before silver layer, full data goes to Firestore bronze layer.