Modernizing a Large Financial Services Enterprise Through Large-Scale Migration to AWS

Large-Scale Migration and Modernization of a Financial Services Enterprise on AWS

VirtueCloud partnered with a large financial services organization to assess, modernize, and migrate over 1,000 servers from a complex on-premises environment to AWS using Infrastructure as Code (Terraform), phased migration waves, and application modernization strategies.

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Modernizing a Large Financial Services Enterprise Through Large-Scale Migration to AWS

Challenge

The customer operated a complex on-premises environment consisting of more than 1,000 servers across multiple data centers with a heterogeneous mix of Windows, Linux, enterprise databases, and .NET applications. Key challenges included End-of-Life (EOL) operating systems, legacy framework dependencies, complex interdependencies across hundreds of applications, elevated security and compliance risks, high operational overhead, and aggressive timelines requiring minimal business disruption.

Solution

1

Executed a comprehensive discovery and assessment of infrastructure, application dependencies, operating systems, and databases.

2

Adopted Infrastructure as Code (IaC) using reusable Terraform modules to automate landing zone deployment, networking, IAM, and security controls.

3

Categorized workloads into Rehost (AWS MGN), Replatform, and Application Modernization (.NET framework upgrades, OS upgrades, and library updates) strategies.

4

Migrated database workloads using AWS Database Migration Service (AWS DMS) and Amazon RDS.

5

Executed migration in controlled waves to minimize operational downtime and risk.

5-Phase Migration & Modernization Framework

Phase 1 – Discovery and Assessment

  • •Detailed assessment to map dependencies, inventory infrastructure, evaluate OS compatibility, and measure migration readiness.

Phase 2 – Planning

  • •Grouped applications into controlled migration waves based on business criticality, dependencies, and technical readiness.

Phase 3 – Modernization

  • •Executed OS upgrades, .NET framework modernization, dependency resolution, and compatibility validation before migration.

Phase 4 – Migration

  • •Performed infrastructure replication, application testing, cutover execution, and post-migration validation using automated wave delivery.

Phase 5 – Operational Readiness

  • •Integrated workloads with AWS centralized monitoring, automated backup, systems management, and cloud governance frameworks.

Application Stack

LayerTechnology
Compute & StorageAmazon EC2, Amazon EBS, Amazon S3
Networking & SecurityAmazon VPC, Elastic Load Balancing, AWS IAM
Migration ServicesAWS Application Migration Service (AWS MGN), AWS Database Migration Service (AWS DMS)
DatabasesAmazon RDS, SQL Server / Enterprise Databases
Management & GovernanceAWS Systems Manager, Amazon CloudWatch, AWS Backup
Infrastructure AutomationTerraform (IaC)
Legacy Operating Systems & FrameworksLinux, Windows Server (2000 through 2022), .NET Framework

Smart Workflow Automation

Automated Wave Deployment

Terraform Provisioning -> AWS MGN Replication -> Testing & Validation -> Production Cutover -> Governance Integration

A repeatable workflow enabling quick environment provisioning, smooth workload replication, zero-data-loss cutovers, and immediate operational integration.

Infrastructure Optimization

Cloud Governance & Operations

  • Centralized monitoring using Amazon CloudWatch.
  • Automated system administration using AWS Systems Manager.
  • Enterprise-wide backup policies via AWS Backup.

Automation & Scalability

  • Reusable Terraform modules for scalable, repeatable account and network provisioning.
  • On-demand compute scaling replacing fixed on-premises hardware capacity.

Key Solutions

Infrastructure as Code (IaC) Automation

Used Terraform to automate AWS account provisioning, networking, and governance, accelerating migration wave readiness and eliminating manual configuration overhead.

Targeted Application Modernization

Upgraded legacy .NET applications, remediated third-party library dependencies, and replaced End-of-Life operating systems prior to migration.

Phased Wave Migration Strategy

Utilized AWS MGN and AWS DMS to replicate and cut over workloads in controlled waves, ensuring business continuity for critical financial operations.

Objectives & Key Results

Objective 1: Migrate 1,000+ server infrastructure to AWS

01

Successfully moved all workloads with minimal operational disruption.

02

Reduced reliance on aging on-premises data centers.

Objective 2: Eliminate Technical Debt & EOL Risk

01

Replaced EOL operating systems across Windows and Unix platforms.

02

Modernized legacy .NET application frameworks.

Objective 3: Accelerate Delivery & Improve Governance

01

Automated AWS landing zone and environment setup via Terraform.

02

Strengthened security posture and disaster recovery capabilities.

Business Impact

1,000+ workloads migrated smoothly to AWS
Scale
Eliminated EOL operating systems and reduced legacy technical debt
Risk Reduction
Accelerated deployment velocity and reduced manual setup via Terraform
Efficiency
Enhanced disaster recovery and centralized cloud governance
Resilience

Project Outcome

The customer successfully transitioned over 1,000 workloads to a secure, scalable, and standardized AWS environment. By pairing IaC automation with targeted application modernization, the organization eliminated critical EOL risks, reduced operational overhead, and established a future-proof cloud foundation.

Future Roadmap

The resulting AWS platform serves as a standardized baseline capable of supporting ongoing operational excellence, advanced cloud-native innovation, and future application modernizations.