Scholastic Asia AWS Implementation & Cost Optimization#
Program Scope#
This initiative modernized cloud foundations across networking architecture, provisioning standards, and cost governance controls. The environment moved from reactive operations — where changes were made manually and inconsistently — to a structured, policy-driven cloud platform where every change is deliberate, validated, and traceable.
Modernization Workstreams#
Network Architecture Restructuring
The existing VPC architecture had accumulated technical debt — overly permissive security groups, flat subnet design, and weak boundary enforcement. The redesign addressed all of it.
Key changes implemented:
- Clear separation of public and private subnets with appropriate routing boundaries
- Hardened route table design and explicit path controls between zones
- Optimized S3 gateway endpoint connectivity to eliminate unnecessary data egress
- Enforced stricter Network ACL policies at the subnet boundary level
- Applied least-privilege Security Group rules across all compute resources
Outcome
Reduced exposure risk and lateral movement surface, improved workload isolation between tiers, and established a stronger, auditable network security baseline.
Terraform-Driven Delivery Model
Manual infrastructure changes were replaced with a structured Terraform-based delivery model — every resource defined in code, every change going through a controlled pipeline.
Implementation:
- Rebuilt infrastructure using modular Terraform design patterns for reusability and clarity
- Source stored in Bitbucket with full change history and access controls
- Terraform plans executed through CI/CD pipelines — no manual console changes permitted
Governance Effect
Every infrastructure change passed automated validation before reaching the environment. This eliminated configuration drift, reduced human error, and created a complete audit trail of every change made to the platform.
Outcome
Infrastructure became predictable, reproducible, and safe to change — the foundation for all future platform growth.
Systematic Cost Reduction
Cloud costs had grown without governance controls. A structured audit and optimization program addressed both recurring waste and architectural inefficiency.
Optimization actions taken:
- Applied EC2 Savings Plans to committed workloads for significant compute discounts
- Right-sized instance types based on actual utilization data — not assumed capacity
- Removed unused Elastic IP addresses accumulating idle charges
- Cleaned orphaned snapshots that were consuming storage without purpose
- Deleted stale AMIs no longer referenced by any active infrastructure
- Removed unattached EBS volumes left behind by terminated instances
- Transitioned S3 backup data to Glacier storage class for long-term cost reduction
Result
Significant reduction in monthly AWS spend. Resource utilization efficiency improved, and cloud spending shifted from reactive consumption to managed, governed investment.
Security Controls Strengthened
Security improvements were applied across network policy, access governance, and attack surface reduction — not as a separate project, but embedded into the modernization itself.
Controls enforced:
- VPC Network ACL policy boundaries tightened at the subnet level
- Security Group rules reviewed and restricted to verified required access only
- Unused and orphaned resources removed to eliminate unnecessary attack surface
- IAM roles and policies audited and restructured under least-privilege principles
- Unmanaged or overly broad permissions revoked across all accounts
Outcome
The AWS environment became more structured, auditable, and defensible — operating under a consistent least-privilege model with clearly defined access boundaries and no unnecessary exposure.
Implementation Summary#
| Domain | Actions Implemented | Measurable Value |
|---|---|---|
| Network Architecture | Subnet separation, route hardening, ACL and Security Group enforcement | Better segmentation, reduced exposure, stronger workload isolation |
| Delivery Governance | Terraform modules + Bitbucket + CI/CD pipeline validation | No configuration drift, complete change audit trail, safer deployments |
| Cost Management | Savings Plans + lifecycle cleanup + storage class tiering | Lower recurring spend, improved utilization, governed cloud investment |
| Security Posture | IAM review + access boundary tightening + resource cleanup | More auditable, defensible environment under least-privilege model |
Business Impact#
- Improved platform reliability through cleaner architecture boundaries and consistent configuration.
- Reduced security risk through least-privilege enforcement, network hardening, and attack surface reduction.
- Lowered cloud run-rate cost through structured, systematic optimization across compute, storage, and network resources.
- Established a repeatable governance model for all future AWS growth — changes follow the same controlled, auditable process.
Closing Notes#
This implementation delivered a balanced AWS strategy: high-performing infrastructure, enforceable governance, stronger security controls, and sustainable cost efficiency — not as trade-offs against each other, but as outcomes that reinforce one another when the architecture is built right.