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✍️ MamunTools
📅 December 30, 2025
🏷️ API Design

🔐 Designing a Secure, Scalable API Gateway Architecture (WSO2 APIM)

A production-grade API Gateway architecture using WSO2 APIM—designed for secure external access, high-throughput internal APIs, defense-in-depth, and built-in observability and monetization.

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In modern enterprises, APIs are no longer just integration points — they are business products that must be secure, observable, scalable, and monetizable.

Recently, I worked on designing an enterprise-grade API Gateway architecture using WSO2 API Manager, focusing on both external partners and high-throughput internal consumers.

Some key design principles behind this architecture 👇


🔹 Clear separation of concerns

- External clients/partners can connect via Internet or VPN

- Internal services follow a low-latency, high-trust path

- Security policies differ, but governance remains centralized


🔹 Defense in depth

- DDoS protection at the edge (before traffic even reaches the gateway)

- NGINX as a dedicated load balancer (HA, health checks, TLS handling)

- OAuth2 / JWT / mTLS depending on trust level and use case


🔹 Scalable API runtime

- Multiple WSO2 API Gateway instances for horizontal scalability

- Stateless gateway design for easier scale-out

- Fine-grained rate limiting, throttling, and spike protection


🔹 Fast internal API consumption

- Local JWT validation (no introspection per request)

- mTLS for service-to-service communication

- Designed for heavy internal usage without unnecessary latency


🔹 Observability & monetization built-in

- End-to-end monitoring, metrics, tracing, and correlation IDs

- Usage metering for billing, chargeback, or partner monetization

- PostgreSQL HA setup with PITR for reliability


This kind of architecture works well for banking, fintech, government, and large enterprise platforms, where availability, security, and auditability are non-negotiable.


Architecture is not about tools — it’s about making the right trade-offs, early.


#APIGateway #WSO2 #SoftwareArchitecture #IntegrationArchitecture

#APIManagement #Fintech #BankingIT #CloudArchitecture #SystemDesign


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