Modernizing Payment Workloads:
AWS API Gateway for scalability and compliance

A major payment processing leader in Latin America, enabling merchants and end-users to conduct secure financial transactions required an API management layer capable of securing, monitoring, and scaling requests across multiple microservices and accounts.

The Client

Our client is a major cash payment service in Latin America that enables people to pay for various bills, taxes, and online purchases at an extensive network of thousands of physical locations, including supermarkets, convenience stores, and kiosks. When a customer chooses their services for an online transaction, they receive a unique voucher with a barcode, which they then present and pay for with cash at any affiliated store. This system is crucial for a country with a significant unbanked population, as it provides a secure and accessible way for individuals to manage their financial obligations and participate in e-commerce without needing a bank account or credit card.

Challenges

Their workloads relied on legacy architecture, which used Elastic Beanstalk applications and direct integrations between services. This approach created:

Limited API Governance: Lack of a centralized API layer led to fragmented authentication and inconsistent security policies across services.
Scaling Bottlenecks: Payment peaks during seasonal events overwhelmed backend applications, with no fine-grained traffic control mechanisms.
Compliance Gaps: PCI DSS required stronger isolation of payment services and immutable logging of API activity.
Operational Complexity: Updating or versioning APIs often involves manual changes across multiple environments, increasing error risk.

The immediate business risk involved transaction failures under peak loads. Long-term risks included regulatory penalties and decreased merchant confidence.

Why AWS

Facing challenges with limited API governance, scaling bottlenecks, and compliance gaps, the client chose AWS to modernize its infrastructure by leveraging key services, such as Amazon API Gateway and AWS Lambda. API Gateway would serve as a centralized, secure layer, solving the issues of fragmented authentication and operational complexity by providing consistent policies and simplified versioning.

For scalability, this service, combined with the serverless, auto-scaling power of Lambda, would automatically handle massive transaction peaks, eliminating the risk of failures during seasonal events.

Finally, AWS provides the necessary tools for compliance, such as AWS CloudTrail for immutable logging and Amazon VPC for network isolation, which directly addresses the PCI DSS requirements and mitigates long-term regulatory risks.

Why Teracloud

As an AWS Advanced Consulting Partner, Teracloud possesses certified expertise in building secure, scalable, and resilient cloud infrastructures, which directly aligns with the client's needs for solving scaling bottlenecks and compliance gaps. We specialize in a range of relevant services that not only allow us to migrate the client's legacy architecture but also implement modern solutions like Amazon API Gateway and AWS Lambda to resolve API governance and performance issues.

By leveraging our knowledge of AWS best practices and the AWS Well-Architected Framework, the client can confidently modernize their platform, ensuring operational excellence, mitigating business risks, and freeing their own teams to focus on core business innovation.

Goals and Objectives

Business Goal: Deliver a highly secure, compliant, and scalable payment API platform capable of processing thousands of concurrent transactions seamlessly.

Technical Goal: Implement Amazon API Gateway as the unified entry point for all payment services, ensuring central security, scalability, and observability while integrating with serverless and container-based workloads.

The Solution

We helped the client adopt an API-first modernization strategy where Amazon API Gateway acts as the single, secure interface between clients and backend services. The architecture includes:

Unified API Layer: All critical services (transaction gateway, fraud detection, merchant dashboard) exposed through API Gateway endpoints.
Integration with Lambda & ECS: Backend logic handled by AWS Lambda for lightweight functions and ECS for long-running services.
Centralized Security: API Gateway configured with IAM authorization, WAF integration, SSL certificates, and throttling policies to prevent abuse.
CI/CD Deployment: Endpoints versioned and deployed using Terraform and CodePipeline, ensuring reproducibility across Dev, QA, Integration, and Production accounts.
Compliance-Ready Logging: All API calls logged centrally via CloudWatch and shipped to immutable logging accounts in AWS Organizations.

Results

Reduced Failures: Centralized throttling reduced peak-load transaction failures by 30%.
Improved Compliance: PCI DSS audits streamlined with consolidated API logging and IAM-based access control.
Accelerated Deployments: Versioned APIs in API Gateway reduced rollout time for new payment features by 50%.
Operational Savings: Eliminated the need for custom gateway services, lowering maintenance costs.

Moving Forward

Incremental Rollout: Introducing API Gateway service by service reduced migration risk.
Early Security Integration: Defining throttling and WAF policies upfront prevented performance degradation under high load.
Cross-Team Alignment: Aligning developers, security, and compliance stakeholders was critical to API-first adoption success.

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Modernizing Payment Workloads: AWS API Gateway for scalability and compliance