Secure Multi-Account AWS Environment for Financial Services
Executive Summary
A leading regional financial institution established a secure, PCI-DSS Level 1 compliant AWS environment using AWS Control Tower, Security Hub, and comprehensive governance controls. DG Global Technology designed and implemented a multi-account architecture spanning 50+ AWS accounts with automated compliance reporting, achieving PCI-DSS certification in 4 months, zero security incidents in 18 months of operation, and 80% reduction in manual security reviews through automation.
Customer Background
A digital-first financial institution offering retail banking, business banking, payment processing, and wealth management services across Hong Kong, Singapore, Malaysia, and Thailand. The company operates a modern digital banking platform with strict data residency requirements and comprehensive audit trail obligations.
Key Stats: 3,500+ employees, 2M+ retail customers, 50,000+ business accounts, $50B+ annual transaction volume, PCI-DSS Level 1, MAS & HKMA regulated
Business Challenge
The institution needed to modernize their technology infrastructure while meeting stringent regulatory compliance requirements including PCI-DSS Level 1 for payment card processing, data residency mandates across multiple jurisdictions, and comprehensive security audit capabilities.
Key Challenges:
- Regulatory Compliance: Required PCI-DSS Level 1 certification within 6 months to expand payment processing services
- Data Residency Requirements: Must maintain customer data within specific geographic boundaries (Hong Kong, Singapore data separation)
- Security Governance: Needed centralized security monitoring and automated compliance reporting across 50+ application teams
- Audit Trail Requirements: Regulatory mandate for comprehensive, immutable audit logs retained for 7 years
- Multi-Account Complexity: Required isolated environments for 50+ business units with centralized governance
- Network Segmentation: Strict requirements for network isolation between PCI-DSS cardholder data environment and non-CDE systems
- Incident Response: Needed automated security incident detection and response with < 15 minute detection time
AWS Solution
DG Global Technology designed and implemented a comprehensive AWS landing zone using AWS Control Tower with automated guardrails, centralized security monitoring, and infrastructure-as-code for consistent compliance enforcement across all accounts.
AWS Services Utilized
AWS Control Tower
Automated multi-account environment setup with 50+ accounts organized by organizational units with preventive guardrails
AWS Security Hub
Centralized security posture management aggregating findings from 15+ AWS security services
Amazon GuardDuty
Intelligent threat detection analyzing VPC Flow Logs, CloudTrail logs, and DNS logs for malicious activity
AWS Config
Continuous configuration compliance monitoring with 120+ managed rules for PCI-DSS requirements
AWS KMS
Customer-managed encryption keys with automatic rotation for all data encryption requirements
AWS Transit Gateway
Hub-and-spoke network topology enabling secure connectivity between accounts and on-premises
Architecture Highlights
- Multi-Account Structure: Security OU (audit, security tooling), Production OU (20+ accounts), Development OU (15+ accounts), Shared Services OU
- Network Architecture: Hub-and-spoke topology with Transit Gateway and inspection VPC
- Data Residency & Encryption: Geographic-specific AWS regions with data residency policies, all data encrypted at rest with KMS
- Identity & Access Management: IAM Identity Center with SAML federation, least-privilege IAM policies, just-in-time access
- Compliance Automation: 120+ AWS Config rules monitoring PCI-DSS compliance, automated remediation using Lambda
Implementation Details
Timeline: 4 months
Team Size: 10 engineers (5 DG Global Technology security specialists, 5 customer internal team)
Methodology: AWS Well-Architected Security Pillar principles
Key Implementation Phases
- Security Architecture Design: Security requirements workshop, multi-account structure design, security controls matrix mapping
- Landing Zone Deployment: Deployed AWS Control Tower with customized guardrails, established organizational structure with 50+ accounts
- Security Services Integration: Enabled Security Hub, deployed GuardDuty, configured Macie for sensitive data discovery
- Network & Identity Setup: Deployed Transit Gateway, configured Network Firewall, implemented IAM Identity Center
- Application Migration: Migrated payment processing application to PCI-DSS compliant CDE VPC
- Compliance Validation: Internal security assessment, engaged Qualified Security Assessor for PCI-DSS audit
Results and Benefits
4 months
PCI-DSS Certification
0
Security Incidents (18mo)
100%
Automated Compliance
Quantifiable Results
- Rapid PCI-DSS Certification: Achieved PCI-DSS Level 1 certification in 4 months (vs. 12-18 month industry average)
- Zero Security Incidents: Zero security breaches or data loss incidents in 18 months of production operation
- Automated Compliance: 100% automated compliance reporting, eliminating 200+ hours/month of manual audit preparation
- Security Review Efficiency: Reduced manual security reviews by 80% through automated Security Hub assessments
- Incident Detection: Average detection time reduced from 4 hours to 8 minutes using GuardDuty
- Audit Readiness: Continuous audit readiness with real-time dashboards, reducing audit prep from 3 months to 2 days
Business Impact
- Business Expansion: Enabled launch of payment processing services in 2 new markets (Thailand, Malaysia)
- Revenue Growth: Unlocked $50M new revenue stream from payment processing services
- Time-to-Market: Reduced new application deployment from 6 months to 2 weeks through automated account vending
- Regulatory Confidence: Successfully passed 4 regulatory audits (MAS, HKMA, PCI-DSS, internal) with zero findings
- Innovation Velocity: Development teams launched 25 new features in first year using compliant-by-default infrastructure
DG Global Technology's expertise in AWS security architecture was critical to our successful cloud transformation. They didn't just help us achieve PCI-DSS Level 1 certification in record time, they established a comprehensive security foundation that scales with our business. The automated compliance reporting has transformed our audit process from a quarterly nightmare into a continuous, transparent process. The combination of zero security incidents and 80% reduction in manual security work has exceeded our expectations.
— David Lim, Chief Information Security Officer
About DG Global Technology
DG Global Technology is an AWS Advanced Consulting Partner and Managed Service Partner specializing in enterprise cloud transformation across ASEAN markets. With 50+ AWS certifications and 5+ years of partnership experience, we deliver comprehensive managed services including 24/7 monitoring, proactive optimization, security management, and cost governance.