🚫 Stop Letting Legacy or Third-Party APIs Pollute Your Architecture
Claudio Romão
🧱 What’s the Real Problem?
You're building a clean, modern app in the cloud. Everything is scalable, testable, and versioned. But then… you need to call a legacy system. Or worse — integrate with a third-party API you don’t control.
💡 Anti-Corruption Layer for The Rescue
The Anti-Corruption Layer (ACL) pattern, from Eric Evans’ Domain-Driven Design, is a proven way to protect your architecture when working with incompatible systems — legacy or external.
It acts as a façade or adapter between two systems that don’t share the same structure, semantics, or reliability guarantees.
Instead of letting legacy or external quirks leak into your clean codebase, you isolate them behind a well-defined translation layer.
🔧 Use Cases
✅ Gradual migrations — calling into a legacy system without corrupting your new service
✅ Third-party integrations — external APIs you don’t control, wrapped in a safe boundary
✅ Bounded context protection — mapping external terminology to internal domain language
✅ Contract enforcement — avoid leaking unstable or loosely typed data into your app
🛠️ How to Implement in Azure
| Scenario | Tool |
| Translating legacy SOAP or XML APIs | Azure Logic Apps or Functions |
| Consistent external API access | Azure API Management as a gateway façade |
| Rich translation logic or orchestration | .NET microservice or Durable Functions |
| Developer productivity | Backstage template + reusable ACL layer per service |
This lets your modern app speak its own language — while safely interoperating with the mess outside.
📈 Aligns with Azure Well-Architected Framework
This pattern directly supports Operational Excellence by:
Avoiding technical debt from dirty integration hacks
Supporting staged migration without blocking new features
Making monitoring, alerting, and retry policies explicit
🚨 Watch Out For…
☁️ Adds complexity and latency
☁️ Needs to be maintained like any microservice
☁️ Might grow too large if not scoped per interaction boundary
But when applied correctly, it can save months of cleanup and risk reduction down the road.
💬 Are You Using ACL?
Have you wrapped an external system with a translation layer?
Habe you create this layer in your Cloud Aruchitecture?
Are ACLs part of your platform engineering toolkit?
Let’s talk 👇
#Azure #CloudArchitecture #DevOps #PlatformEngineering #Microservices #LegacyMigration #SoftwareDesign #IntegrationPattern #AntiCorruptionLayer
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