Anonymized enterprise case study
AWS Platform Modernization
Eunimo reframed a legacy modernization problem into a Terraform-defined AWS delivery platform: a protected public front door, private ECS and data boundaries, blue-green release promotion, and a control layer for observability, security, and operating response.
The client was not modernizing for cloud optics. Public ingress was too loosely controlled, releases were too risky to promote confidently, and runtime visibility was too fragmented to support accountable operations. The architecture had to solve those business constraints while keeping the platform live throughout the transition.
The target state was designed around three visible requirements in the diagram: an explicit public front door, a private application and data boundary, and a control layer for release, security, and operations. The architecture earns its complexity by making those relationships legible.
Why the business changed now.
The program was framed as incremental modernization. Business capabilities could be carved out over time, reducing cutover risk and allowing investment to show value earlier.
- Release pressure: Ship backend change without full-platform cutovers. The platform needed safer release mechanics. Blue-green promotion and bounded services made backend change possible without turning every deployment into a broad platform event.
- Ingress control: Harden the public entry path. Public traffic had to be routed, filtered, terminated, and balanced through one clear control layer instead of scattered point solutions.
- Operating visibility: Make runtime activity operationally accountable. Telemetry, alerting, and security signals had to become an operating surface. CloudWatch, Security Hub, Inspector, Systems Manager, Slack, and Teams were positioned to surface issues early and keep ownership clear.
- Protect internet-facing traffic through one governed entry path.
- Promote releases through blue-green workflows instead of in-place cutovers.
- Keep runtime and data services private behind bounded network controls.
- Push operational and security signals into response channels before incidents widen.
Protected ingress, private runtime, and governed control layers.
The target state was designed around three visible requirements in the diagram: an explicit public front door, a private application and data boundary, and a control layer for release, security, and operations. The architecture earns its complexity by making those relationships legible.
- Protected ingress: Route 53, WAF, CloudFront, certificates, and load balancing create one governed public entry path.
- Blue-green releases: GitHub, ECR, CodeDeploy, ECS, and Fargate form a controlled promotion chain.
- Managed control plane: CloudWatch, Security Hub, Inspector, IAM, KMS, Secrets Manager, and Systems Manager keep the platform governable.
- Scale: Scale was concentrated where demand actually appears: the public edge, the service tier, and the Fargate runtime. Route 53 and CloudFront shape traffic before requests reach the application tier. Load balancing and ECS keep ingress scale separate from runtime scale. Fargate, RDS, and ElastiCache support growth without exposing data services directly.
- Observability: Observability was designed in as an operating surface, not added after the fact. CloudWatch provides the main telemetry and alarm layer. Teams and Slack receive signals quickly enough to support response loops. Systems Manager supports action once issues are identified.
- Security: Security was layered across ingress, identity, secrets, encryption, and runtime scanning so the environment stayed governable as delivery speed increased. WAF, certificates, and private boundaries narrow the exposed surface area. IAM, Secrets Manager, and KMS keep identity and protected material under explicit control. Security Hub and Inspector turn review into a continuous operating function.
- Delivery control: The architecture was wired for controlled software movement across source, artifacts, deployment promotion, and infrastructure change. GitHub workflows feed versioned artifacts into ECR and downstream services. CodeDeploy manages blue-green promotion instead of ad hoc cutovers. Terraform keeps infrastructure changes reviewable and repeatable.
Built to be operated, audited, and evolved continuously.
The delivery model is part of the architecture, not something wrapped around it later. GitHub, ECR, CodeDeploy, ECS, Terraform, and the surrounding control services create one repeatable promotion path where change, rollback, telemetry, and governance stay connected.
- Blue-green delivery as the default release path: GitHub, ECR, CodeDeploy, and ECS were structured as one promotion chain, reducing deployment risk and making rollback more defensible than in-place change.
- Managed governance around the runtime: IAM, Secrets Manager, KMS, Security Hub, Inspector, CloudWatch, and Systems Manager were positioned as explicit controls around the runtime.
- Signals move to people as well as systems: Alarms and operational signals were routed into Slack and Teams, not left inside dashboards alone.
The business case translated into an operating advantage.
The result was more than a technical migration. The client gained a platform with a protected front door, a controlled release chain, private runtime boundaries, and clearer operating signals across security and observability.
- Safer public-facing change with a clearer ingress model: Route 53, WAF, CloudFront, certificates, and load balancing now work as one explicit front door.
- Lower release risk through controlled promotion: Blue-green deployment and versioned artifacts create a more defensible release model than changing live services in place.
- Stronger operational maturity around the runtime: CloudWatch, Security Hub, Inspector, Systems Manager, Slack, and Teams turn the platform into a monitored operating system, not just a deployed workload.
- More governed scale across edge, compute, and data: Internet entry, runtime execution, and stateful data are now separated clearly enough for growth to happen without blurring risk boundaries.
Protected ingress. Safer releases. A platform built for governed scale.
The trade-off stayed explicit throughout: microservices add complexity, so the platform had to earn that complexity back through business outcomes. Here, protected ingress, controlled promotion, bounded runtime and data services, and operating signal flow made the shift commercially defensible.