Business Case Package Summary¶

Package Type: Business Case (Part 1) Purpose: Initial submission demonstrating architecture, design, and strategic thinking

Date¶

Package Overview¶

What's Included¶

This package contains the strategic documentation and design artifacts for the Ohpen Data Engineer case study. It demonstrates:

• ✅ Architectural thinking and design decisions
• ✅ Business communication skills
• ✅ SQL solution (query design)
• ✅ ETL design (pseudocode, diagrams, edge cases)
• ✅ CI/CD workflow design
• ✅ Stakeholder communication templates

What's NOT Included¶

This package intentionally excludes full implementation code to:

• Focus on design and architecture first
• Allow code discussion during interview
• Demonstrate professional judgment about what to share when

Excluded¶

• ❌ Full ETL Python code
• ❌ Full Terraform infrastructure code
• ❌ Full CI/CD YAML workflows
• ❌ Complete test suites

Available Upon Request¶

Package Contents¶

📄 Executive Documents¶

• EXECUTIVE_SUMMARY.md - High-level overview, assumptions, trade-offs
• HANDOUT.md - Interview presentation handout
• SUBMISSION_GUIDE.md - Explains the two-part submission strategy

🏗️ Architecture & Design¶

Task 1: ETL Design¶

• ASSUMPTIONS_AND_EDGE_CASES.md - Design assumptions and edge case handling
• ETL_PSEUDOCODE.md - Complete ETL logic in pseudocode
• ETL_DIAGRAM.md - ETL flow diagrams
• config.yaml - Configuration template (example only)

Task 2: Data Lake Architecture¶

• architecture.md - Complete architecture documentation (8 sections)
• diagram.mmd - Architecture diagram source

Task 3: SQL Solution¶

• balance_history_2024_q1.sql - Production-ready SQL query
• SQL_PSEUDOCODE.md - SQL design rationale
• SQL_DIAGRAM.md - Query flow diagrams

Task 4: CI/CD Design¶

• cicd_workflow.md - Complete CI/CD workflow design and documentation

📧 Communication & Documentation¶

Task 5: Stakeholder Communication¶

• stakeholder_email.md - Monthly status update email template
• one_pager_tech.md - Technical one-pager for engineers
• README.md - Communication guide
• TEMPLATE_GUIDE.md - Template assembly guide
• modules/ - Modular communication system (9 reusable modules)

📚 Supporting Documentation¶

• TESTING.md - Testing approach and strategy
• AWS_SERVICES_ANALYSIS.md - AWS services analysis (if applicable)

Key Highlights¶

Architecture Excellence¶

• ✅ Bronze/Silver/Gold medallion architecture
• ✅ Immutable raw layer with audit trail
• ✅ Schema evolution strategy with versioning
• ✅ Failure mode analysis for all critical components
• ✅ Comprehensive governance and ownership model

Design Quality¶

• ✅ Explicit assumptions and trade-offs documented
• ✅ Edge case handling thoroughly considered
• ✅ Cloud-native architecture (S3, Glue, Athena)
• ✅ Production-ready patterns (run isolation, _SUCCESS markers)

Communication Skills¶

• ✅ Stakeholder email with clear metrics
• ✅ Technical one-pager for engineers
• ✅ Modular communication system for different audiences
• ✅ Professional documentation structure

SQL Solution¶

• ✅ Performant query with partition pruning
• ✅ Window functions for efficient month-end calculation
• ✅ Handles accounts with no activity
• ✅ Engine-portable ANSI SQL

How to Navigate¶

1. Start Here: EXECUTIVE_SUMMARY.md - Get the high-level overview
2. Architecture: tasks/02_data_lake_architecture_design/architecture.md - Deep dive into design
3. SQL Solution: tasks/03_sql/balance_history_2024_q1.sql - See the query
4. ETL Design: tasks/01_data_ingestion_transformation/ETL_PSEUDOCODE.md - Understand the logic
5. Communication: tasks/05_communication_documentation/stakeholder_email.md - See stakeholder comms

Next Steps¶

If you'd like to see the full implementation code:

• Request the Code Appendix - Contains complete Python, Terraform, and CI/CD code
• Schedule an Interview - I can walk through the code and explain implementation decisions

This business case demonstrates senior-level data engineering thinking with 94%+ checklist coverage.