Data-Centric Lakehouse AI

AI tightly integrated with a data platform. Combines a lakehouse architecture (ADLS Gen2 + Databricks + Delta Lake) with Azure AI Search and Azure OpenAI. Data flows through medallion zones (raw → curated → serving) with AI at the serving layer.

~$8,350/mo
13
Azure Services
~$8,350
Monthly Cost
3 Zones
Medallion Arch.
3 ADLS
Data Accounts

Overview

The Data-Centric Lakehouse AI pattern is built on the medallion architecture — data flows through Raw, Curated, and Serving zones. Databricks handles ETL and feature engineering, three separate ADLS Gen2 accounts maintain zone isolation, and AI Search + OpenAI serve the AI layer.

This is the ideal pattern for organizations with large-scale data platforms that want to layer AI on top of existing data assets.

Key Characteristics
  • Medallion Architecture — Raw → Curated → Serving with dedicated ADLS per zone
  • Databricks Premium — VNet-injected, Delta Lake, Spark ETL
  • 3 ADLS Gen2 Accounts — Data isolation per medallion zone
  • AI Search with 2 Replicas — High availability for search queries
  • GPT-4o (40K TPM) — Higher quota for data-heavy inference
OpenAI Models
GPT-4o40K TPM
text-embedding-3-large120K TPM
AI Search Config
SKUStandard
Replicas2 (HA)
Partitions1
SemanticStandard
Databricks
TierPremium
VNetInjected

Medallion Architecture

Raw Zone

Bronze layer — ingestion & landing

landing/ raw/ archive/

{base}{env}raw

Curated Zone

Silver/Gold — transformed & clean

silver/ gold/ delta-tables/

{base}{env}curated

Serving Zone

AI-ready — embeddings & vectors

embeddings/ vector-indexes/ model-artifacts/ documents/

{base}{env}serving

Architecture Diagram

graph TB
    subgraph LHVNet["Lakehouse + AI VNet 10.40.0.0/16"]
        subgraph DBX["Databricks VNet-Injected"]
            DBPUB["Public Subnet /22"]
            DBPRV["Private Subnet /22"]
        end
        subgraph DataZones["Medallion Data Zones"]
            RAW["ADLS Gen2 — Raw<br/>landing / raw / archive"]
            CUR["ADLS Gen2 — Curated<br/>silver / gold / delta"]
            SRV["ADLS Gen2 — Serving<br/>embeddings / vectors"]
        end
        subgraph AILayer["AI Layer"]
            AIS["Azure AI Search<br/>Standard, 2 replicas"]
            AOAI["Azure OpenAI<br/>GPT-4o 40K TPM"]
        end
        subgraph App["Application"]
            APPSVC["App Service<br/>RAG Application<br/>VNet-integrated"]
        end
        subgraph Support["Support Services"]
            KV["Key Vault"]
            MON["Log Analytics + App Insights"]
        end
    end
    DBX -->|"ETL / Feature Eng"| RAW
    RAW -->|"Transform"| CUR
    CUR -->|"Vectorize"| SRV
    SRV --> AIS
    SRV --> AOAI
    APPSVC --> AIS
    APPSVC --> AOAI
    AIS --> MON
    AOAI --> MON
    DBX --> MON
    AOAI --> KV
          

Bill of Materials

#ServiceResource NameSKU / TierPurposeMonthly Cost
1Azure Databricks{base}-{env}-dbwPremium, VNet-injectedSpark ETL, feature engineering, Delta Lake~$2,800
2Azure OpenAI{base}-{env}-openaiS0GPT-4o (40K TPM) + embeddings (120K TPM)~$2,750
3Azure AI Search{base}-{env}-searchStandard, 2 replicasVector + semantic search (HA)$490.56
4ADLS Gen2 (Raw){base}{env}rawStandard LRS, HNSLanding, raw data, archive~$80
5ADLS Gen2 (Curated){base}{env}curatedStandard LRS, HNSSilver, gold, delta tables~$60
6ADLS Gen2 (Serving){base}{env}servingStandard LRS, HNSEmbeddings, vector indexes, model artifacts~$40
7App Service (opt.){base}-{env}-appP1v3, LinuxRAG application compute~$140
8Key Vault{base}-{env}-kvStandardConnection strings, API keys~$5
9Log Analytics{base}-{env}-lawPerGB2018, 90-dayTelemetry and audit~$35
10Application Insights{base}-{env}-appinsightsWorkspace-basedAPM for App Service + AIIncl.
11VNet{base}-{env}-vnet/16 with 6 subnetsNetwork backboneFree
12Private DNS Zones5 zonesGlobalPrivate name resolution~$2.50
13Private Endpoints7 endpointsOpenAI, Search, Raw-Blob, Raw-DFS, Curated-DFS, Serving-Blob, KV~$51
Estimated Total (Moderate Production)~$8,350/mo

AI Search with 2 replicas provides HA for production search queries. Databricks cost based on Premium DBU consumption.

Service Breakdown

Azure Databricks
Premium~$2,800/mo

VNet-injected Databricks for Spark-based ETL, feature engineering, and Delta Lake operations. Processes data through medallion zones. Public and private subnets each /22.

Azure OpenAI
S0~$2,750/mo

GPT-4o at 40K TPM for inference and text-embedding-3-large at 120K TPM for vectorization. Higher quota than other patterns to handle data-intensive embedding generation.

AI Search (2 Replicas)
Standard$490.56/mo

Production-ready search with 2 replicas for high availability. Standard tier with semantic ranking. Indexes vectors from the Serving zone for RAG queries.

3Ã- ADLS Gen2
Standard LRS~$180/mo total

Three separate storage accounts for medallion architecture: Raw (landing/raw/archive), Curated (silver/gold/delta), Serving (embeddings/vectors/models). All HNS-enabled.

App Service
P1v3 Linux~$140/mo

Optional RAG application compute with VNet integration. Serves as the frontend application that queries AI Search and Azure OpenAI from data in the Serving zone.

7 Private Endpoints
PE + DNS~$54/mo

Private Endpoints for all services: OpenAI, AI Search, Raw-Blob, Raw-DFS, Curated-DFS, Serving-Blob, Key Vault. Five Private DNS Zones for resolution.

Security & Networking

Network
  • Databricks VNet-injected — no public infrastructure
  • All data and AI services via Private Endpoints
  • 5 Private DNS Zones (OpenAI, Search, Blob, DFS, KV)
  • /16 VNet with 6 subnets (DBX pub, DBX prv, App, PE, Data, Mgmt)
  • App Service with VNet Integration
Identity & Data
  • Key Vault with RBAC authorization
  • Managed Identities for all service auth
  • Zone-level RBAC on each ADLS account
  • Delta Lake ACID transactions in Curated zone
  • 90-day log retention for audit

Use Cases

Data Platform + AI

Layer AI on top of existing data lake. Use medallion architecture to feed clean, curated data into AI Search and OpenAI.

Real-Time Analytics + AI

Process streaming data through Databricks, generate embeddings in real-time, serve via AI Search for instant RAG queries.

Enterprise Knowledge Mining

Ingest millions of documents through medallion zones, extract insights via OpenAI, and index for semantic search.

Predictive + Generative AI

Combine traditional ML predictions from Databricks with generative AI explanations from OpenAI for complete analytics.

Constraints & Considerations

ConstraintMitigation
Three ADLS accounts increase management overheadAutomate with Bicep; use consistent naming conventions
Databricks Premium is expensiveUse job clusters with auto-terminate; spot instances for ETL
Data movement between zones adds latencyUse Databricks Delta Live Tables for streaming ETL
AI Search with 2 replicas doubles search costUse 1 replica for dev/test, 2 for production only
Complex VNet with 6 subnetsCareful IP planning; document subnet allocation
Ready to Deploy This Pattern?

Generate a complete deployment spec sheet with GitHub Actions workflow, Bicep file structure, and prerequisite checklist.

Generate Deployment Spec Sheet