Enterprise Data Center to Cloud Migration

Project Overview

This enterprise-scale cloud migration involved moving a financial services company’s entire data center infrastructure to AWS. The project required meticulous planning to ensure compliance with financial regulations while maintaining zero downtime for critical payment processing systems.

Technical Approach

Phase 1: Assessment and Planning

We began with a comprehensive assessment of the existing infrastructure, cataloging over 200 applications and their dependencies. This phase included:

• Application dependency mapping
• Compliance requirement documentation
• Risk assessment and mitigation planning
• Migration wave planning

Phase 2: Foundation Building

The foundation phase established the core AWS infrastructure:

• Multi-AZ VPC design with proper subnet segmentation
• Transit Gateway for hybrid connectivity
• AWS Landing Zone implementation
• Security baseline and guardrails

Phase 3: Migration Execution

Migration waves were executed over 12 months, prioritizing applications based on:

• Business criticality
• Technical complexity
• Interdependencies
• Compliance requirements

Phase 4: Optimization

Post-migration optimization focused on:

• Right-sizing resources based on actual usage
• Implementing Reserved Instances for cost savings
• Performance tuning and monitoring enhancement

Key Learnings

1. Start with the end in mind - Clear success criteria and rollback procedures are essential
2. Communication is critical - Regular stakeholder updates prevented misaligned expectations
3. Automate everything - Infrastructure as Code reduced errors and improved repeatability
4. Test thoroughly - Comprehensive testing in lower environments prevented production issues