Enterprise SQL Architecture

Introduction

At enterprise scale, SQL lives inside a wider data platform: OLTP DBs, replicas, ETL, warehouse, lakehouse, BI, governance, lineage. SQL is the connective tissue.

Understanding the topic

Core concepts to understand:

• OLTP: Postgres/MySQL clusters per service.
• ETL/ELT: dbt, Fivetran into warehouse.
• Warehouse: Snowflake/BigQuery for analytics.
• Lakehouse: Delta/Iceberg for cheap raw storage.
• Governance: catalog, lineage, RBAC.

Syntax reference

Visual workflow / architecture:

Apps ─▶ OLTP DBs ─▶ Replicas
                              │
                              ▼
                          Warehouse / Lakehouse
                              │
                              ▼
                        BI / ML / Reverse-ETL

Real-world use

Stripe, Shopify, Airbnb, Uber — every modern data platform looks like this. SQL is everywhere.

Best practices

• Clear contracts between OLTP, warehouse and apps.
• Lineage + catalog for trust.
• Self-serve analytics without compromising the primary.

Hands-on exercise

Interview preparation — practice these questions:

• Q1. OLTP vs OLAP vs lakehouse.
• Q2. Lineage and catalog tools.
• Q3. Reverse-ETL — what is it?
• Q4. SLAs between OLTP and warehouse.
• Q5. Governance challenges at scale.