Data Architecture

Purpose

Guide architects and platform engineers through strategic data architecture decisions for modern cloud-native data platforms.

When to Use This Skill

Invoke this skill when:

•Designing a new data platform or modernizing legacy systems
•Choosing between data lake, data warehouse, or data lakehouse
•Deciding on data modeling approaches (dimensional, normalized, data vault, wide tables)
•Evaluating centralized vs data mesh architecture
•Selecting open table formats (Apache Iceberg, Delta Lake, Apache Hudi)
•Designing medallion architecture (bronze, silver, gold layers)
•Implementing data governance and cataloging

Core Concepts

1. Storage Paradigms

Three primary patterns for analytical data storage:

Data Lake: Centralized repository for raw data at scale

•Schema-on-read, cost-optimized ($0.02-0.03/GB/month)
•Use when: Diverse data sources, exploratory analytics, ML/AI training data

Data Warehouse: Structured repository optimized for BI

•Schema-on-write, ACID transactions, fast queries
•Use when: Known BI requirements, strong governance needed

Data Lakehouse: Hybrid combining lake flexibility with warehouse reliability

•Open table formats (Iceberg, Delta Lake), ACID on object storage
•Use when: Mixed BI + ML workloads, cost optimization (60-80% cheaper than warehouse)

Decision Framework:

•BI/Reporting only + Known queries → Data Warehouse
•ML/AI primary + Raw data needed → Data Lake or Lakehouse
•Mixed BI + ML + Cost optimization → Data Lakehouse (recommended)
•Exploratory/Unknown use cases → Data Lake

For detailed comparison, see references/storage-paradigms.md.

2. Data Modeling Approaches

Four primary modeling patterns:

Dimensional (Kimball): Star/snowflake schemas for BI

•Use when: Known query patterns, BI dashboards, trend analysis

Normalized (3NF): Eliminate redundancy for transactional systems

•Use when: OLTP systems, frequent updates, strong consistency

Data Vault 2.0: Flexible model with complete audit trail

•Use when: Compliance requirements, multiple sources, agile warehousing

Wide Tables: Denormalized, optimized for columnar storage

•Use when: ML feature stores, data science notebooks, high-performance dashboards

Decision Framework:

•Analytical (BI) + Known queries → Dimensional (Star Schema)
•Transactional (OLTP) → Normalized (3NF)
•Compliance/Audit → Data Vault 2.0
•Data Science/ML → Wide Tables

For detailed patterns, see references/modeling-approaches.md.

3. Data Mesh Principles

Decentralized architecture for large organizations (>500 people).

Four Core Principles:

•Domain-oriented decentralization
•Data as a product (SLAs, quality, documentation)
•Self-serve data infrastructure
•Federated computational governance

Readiness Assessment (Score 1-5 each):

•Domain clarity
•Team maturity
•Platform capability
•Governance maturity
•Scale need
•Organizational buy-in

Scoring: 24-30: Strong candidate | 18-23: Hybrid | 12-17: Build foundation first | 6-11: Centralized

Red Flags: Small org (<100 people), unclear domains, no platform team, weak governance

For full guide, see references/data-mesh-guide.md.

4. Medallion Architecture

Standard lakehouse pattern: Bronze (raw) → Silver (cleaned) → Gold (business-level)

Bronze Layer: Exact copy of source data, immutable, append-only

Silver Layer: Validated, deduplicated, typed data

Gold Layer: Business logic, aggregates, dimensional models, ML features

Data Quality by Layer:

•Bronze → Silver: Schema validation, type checks, deduplication
•Silver → Gold: Business rule validation, referential integrity
•Gold: Anomaly detection, statistical checks

For patterns, see references/medallion-pattern.md.

5. Open Table Formats

Enable ACID transactions on data lakes:

Apache Iceberg: Multi-engine, vendor-neutral (Context7: 79.7 score)

•Use when: Avoid vendor lock-in, multi-engine flexibility

Delta Lake: Databricks ecosystem, Spark-optimized

•Use when: Committed to Databricks

Apache Hudi: Optimized for CDC and frequent upserts

•Use when: CDC-heavy workloads

Recommendation: Apache Iceberg for new projects (vendor-neutral, broadest support)

For comparison, see references/table-formats.md.

6. Modern Data Stack

Standard Layers:

•Ingestion: Fivetran, Airbyte, Kafka
•Storage: Snowflake, Databricks, BigQuery
•Transformation: dbt (Context7: 87.0 score), Spark
•Orchestration: Airflow, Dagster, Prefect
•Visualization: Tableau, Looker, Power BI
•Governance: DataHub, Alation, Great Expectations

Tool Selection:

•Fivetran vs Airbyte: Pre-built connectors vs cost-sensitive
•Snowflake vs Databricks: BI-focused vs ML-focused
•dbt vs Spark: SQL-based vs large-scale processing

For detailed recommendations, see references/tool-recommendations.md and references/modern-data-stack.md.

7. Data Governance

Data Catalog: Searchable inventory (DataHub, Alation, Collibra)

Data Lineage: Track data flow (OpenLineage, Marquez)

Data Quality: Validation and testing (Great Expectations, Soda, dbt tests)

Access Control:

•RBAC: Role-based (sales_analyst role)
•ABAC: Attribute-based (row-level security)
•Column-level: Dynamic data masking for PII

For governance patterns, see references/governance-patterns.md.

Decision Frameworks

Framework 1: Storage Paradigm Selection

Step 1: Identify Primary Use Case

•BI/Reporting only → Data Warehouse
•ML/AI primary → Data Lake or Lakehouse
•Mixed BI + ML → Data Lakehouse
•Exploratory → Data Lake

Step 2: Evaluate Budget

•High budget, known queries → Data Warehouse
•Cost-sensitive, flexible → Data Lakehouse

Recommendation by Org Size:

•Startup (<50): Data Warehouse (simplicity)
•Growth (50-500): Data Lakehouse (balance)
•Enterprise (>500): Hybrid or unified Lakehouse

See references/decision-frameworks.md.

Framework 2: Data Modeling Approach

Decision Tree:

•Analytical (BI) workload → Dimensional or Wide Tables
•Transactional (OLTP) → Normalized (3NF)
•Compliance/Audit → Data Vault 2.0
•Data Science/ML → Wide Tables

See references/decision-frameworks.md.

Framework 3: Data Mesh Readiness

Use 6-factor assessment. Score interpretation:

•24-30: Proceed with data mesh
•18-23: Hybrid approach
•12-17: Build foundation first
•6-11: Centralized

See references/decision-frameworks.md.

Framework 4: Open Table Format Selection

Decision Tree:

•Multi-engine flexibility → Apache Iceberg
•Databricks ecosystem → Delta Lake
•Frequent upserts/CDC → Apache Hudi

Recommendation: Apache Iceberg for new projects

See references/decision-frameworks.md.

Common Scenarios

Startup Data Platform

Context: 50-person startup, PostgreSQL + MongoDB + Stripe

Recommendation:

•Storage: BigQuery or Snowflake
•Ingestion: Airbyte or Fivetran
•Transformation: dbt
•Orchestration: dbt Cloud
•Architecture: Simple data warehouse

See references/scenarios.md.

Enterprise Modernization

Context: Legacy Oracle warehouse, need cloud migration

Recommendation:

•Storage: Data Lakehouse (Databricks or Snowflake with Iceberg)
•Strategy: Incremental migration with CDC
•Architecture: Medallion (bronze, silver, gold)
•Cost Savings: 60-80%

See references/scenarios.md.

Data Mesh Assessment

Context: 200-person company, 5-person central data team

Recommendation: NOT YET. Build foundation first.

•Organization too small (<500 recommended)
•Central team not yet bottleneck
•Invest in self-serve platform and governance

See references/scenarios.md.

Tool Recommendations

Research-Validated (Context7, December 2025)

dbt: Score 87.0, 3,532+ code snippets

•SQL-based transformations, version control, testing
•Industry standard for data transformation

Apache Iceberg: Score 79.7, 832+ code snippets

•Open table format, multi-engine, vendor-neutral
•Production-ready (Netflix, Apple, Adobe)

Tool Stack by Use Case:

Startup: BigQuery + Airbyte + dbt + Metabase (<$1K/month)

Growth: Snowflake + Fivetran + dbt + Airflow + Tableau ($10K-50K/month)

Enterprise: Snowflake + Databricks + Fivetran + Kafka + dbt + Airflow + Alation ($50K-500K/month)

See references/tool-recommendations.md.

Implementation Patterns

Pattern 1: Medallion Architecture

sql

-- Bronze: Raw ingestion
CREATE TABLE bronze.raw_customers (_ingested_at TIMESTAMP, _raw_data STRING);

-- Silver: Cleaned
CREATE TABLE silver.customers AS
SELECT json_extract(_raw_data, '$.id') AS customer_id, ...
FROM bronze.raw_customers
QUALIFY ROW_NUMBER() OVER (PARTITION BY customer_id ORDER BY _ingested_at DESC) = 1;

-- Gold: Business-level
CREATE TABLE gold.fact_sales AS
SELECT s.order_id, d.date_key, c.customer_key, ...
FROM silver.sales s
JOIN gold.dim_date d ON s.order_date = d.date;

Pattern 2: Apache Iceberg Table

sql

CREATE TABLE catalog.db.sales (order_id BIGINT, amount DECIMAL(10,2))
USING iceberg
PARTITIONED BY (days(order_date));

-- Time travel
SELECT * FROM catalog.db.sales TIMESTAMP AS OF '2025-01-01';

Pattern 3: dbt Transformation

sql

-- models/staging/stg_customers.sql
WITH source AS (SELECT * FROM {{ source('raw', 'customers') }}),
cleaned AS (
  SELECT customer_id, UPPER(customer_name) AS customer_name
  FROM source WHERE customer_id IS NOT NULL
)
SELECT * FROM cleaned

For complete examples, see examples/.

Best Practices

•Start simple: Avoid over-engineering; begin with warehouse or basic lakehouse
•Invest in governance early: Catalog, lineage, quality from day one
•Medallion architecture: Use bronze-silver-gold for clear quality layers
•Open table formats: Prefer Iceberg or Delta Lake to avoid vendor lock-in
•Assess mesh readiness: Don't decentralize prematurely (<500 people)
•Automate quality: Integrate tests (Great Expectations, dbt) into CI/CD
•Monitor pipelines: Observability is critical (freshness, quality, health)
•Document as code: Use dbt docs, DataHub, YAML for self-service
•Incremental loading: Only load new/changed data (watermark columns)
•Business alignment: Align architecture to outcomes, not just technologies

Anti-Patterns

•❌ Data swamp: Lake without governance or cataloging
•❌ Premature mesh: Mesh before organizational readiness
•❌ Tool sprawl: Too many tools without integration
•❌ No quality checks: "Garbage in, garbage out"
•❌ Centralized bottleneck: Single team in large org (>500 people)
•❌ Vendor lock-in: Proprietary formats without migration path
•❌ No lineage: Can't answer "where did this come from?"
•❌ Over-engineering: Complex architecture for simple use cases

Integration with Other Skills

Direct Dependencies:

•ingesting-data: ETL/ELT mechanics, Fivetran, Airbyte implementation
•data-transformation: dbt and Dataform detailed implementation
•streaming-data: Kafka, Flink for real-time pipelines

Complementary:

•databases-relational: PostgreSQL, MySQL as source systems
•databases-document: MongoDB, DynamoDB as sources
•ai-data-engineering: Feature stores, ML training pipelines
•designing-distributed-systems: CAP theorem, consistency models
•observability: Monitoring pipeline health, data quality metrics

Downstream:

•visualizing-data: BI and dashboard patterns
•sql-optimization: Query performance tuning

Common Workflows:

End-to-End Analytics:

code

data-architecture (warehouse) → ingesting-data (Fivetran) →
data-transformation (dbt) → visualizing-data (Tableau)

Data Platform for AI/ML:

code

data-architecture (lakehouse) → ingesting-data (Kafka) →
data-transformation (dbt features) → ai-data-engineering (feature store)

architecting-data

Data Architecture

Purpose

When to Use This Skill

Core Concepts

1. Storage Paradigms

2. Data Modeling Approaches

3. Data Mesh Principles

4. Medallion Architecture

5. Open Table Formats

6. Modern Data Stack

7. Data Governance

Decision Frameworks

Framework 1: Storage Paradigm Selection

Framework 2: Data Modeling Approach

Framework 3: Data Mesh Readiness

Framework 4: Open Table Format Selection

Common Scenarios

Startup Data Platform

Enterprise Modernization

Data Mesh Assessment

Tool Recommendations

Research-Validated (Context7, December 2025)

Implementation Patterns

Pattern 1: Medallion Architecture

Pattern 2: Apache Iceberg Table

Pattern 3: dbt Transformation

Best Practices

Anti-Patterns

Integration with Other Skills

Further Reading