Hybrid Cloud Fintech Architecture
Regulated payments platform across AWS and on-premises VMware (anonymized)
Basis: CV: architected hybrid AWS and on-premises infrastructure for Java-based fintech platforms with 24x7 availability and PCI-DSS / SOC2 compliance. Names, topology details and figures are withheld. The published code is a synthetic reference implementation of that pattern — never applied against a real account or host.
Overview
A hybrid design for a high-availability payments platform: Kubernetes workloads on AWS, systems of record on-premises on VMware, private connectivity, segmented networks and tested backup and DR procedures.
Problem
Regulatory and latency constraints keep some systems on-premises, while customer-facing services need cloud elasticity. The boundary between them is where most security and reliability risk lives.
Solution
Treat the hybrid link as a security boundary: segmented networks, explicit allow-lists, encrypted private connectivity, and services designed to degrade gracefully when the link is impaired.
Architecture
AWS
Edge
CloudFront, WAF, ALB
EKS
customer-facing services
Connectivity
Private link
encrypted, redundant tunnels
On-premises
VMware vSphere
core services
Databases
replicated
Controls
Segmentation + ACLs
SIEM / SOC
Backup + DR runbooks
Technology stack
- Amazon EKS
- VMware vSphere / ESXi
- Site-to-Site VPN / private connectivity
- Amazon RDS
- Ansible
- Terraform
- Prometheus
- ELK
Implementation
- Redundant Site-to-Site VPN: two on-prem gateways and two VPN connections (four tunnels total), so a single device or tunnel failure doesn't take down the hybrid link.
- A segmentation module parameterized by zone (edge vs. regulated), with a deny-by-default security group and a Terraform precondition that fails validation outright if the regulated zone's rules would ever allow 0.0.0.0/0.
- A graceful-degradation client: on-prem-dependent calls that hit a connectivity failure are queued to an outbox instead of failing the customer-facing request, with a replay mechanism for once the link recovers.
- Ansible for consistent configuration and patching across cloud and on-prem hosts — one baseline role applied identically to both inventory groups, varying only package manager and network-interface naming.
- DR runbooks with restore tests, not just backup jobs, including a documented synthetic failure and its follow-up.
Security
- Network segmentation aligned with PCI-DSS scope reduction: the regulated zone can only be reached from the edge zone or named management ranges, never the open internet, enforced by a validation that blocks the config from passing otherwise.
- Least-privilege IAM and secrets management with rotation.
- Vulnerability remediation tracked through SOC operations.
Reliability
- Redundant tunnels; services queue work to an outbox and degrade rather than fail outright when the on-prem link is down — verified end to end (queue two calls during a simulated outage, replay both cleanly once healthy).
- Capacity planning and incident response owned for 24x7 workloads.
Cost
- Rightsizing, AMI/snapshot lifecycle and volume cleanup on the AWS side.
Results
No quantified results are published for this project. Figures from client work are confidential, and this portfolio only shows numbers that can be verified or reproduced.
Code & documentation
Lessons learned
- The hybrid link is part of every incident — instrument it as carefully as the applications.
- Degrade-and-queue beats fail-hard: a customer-facing request shouldn't fail just because a dependency three hops away, across a private link, is slow or down.