​​📘 AWS Reference Architecture — Invoking Asynchronous External APIs:

https://d1.awsstatic.com/architecture-diagrams/ArchitectureDiagrams/invoking-asynchronous-external-apis-ra.pdf

1️⃣ Set up Step Functions
2️⃣ Send the task token and the request payload
3️⃣ Use Lambda to poll SQS and trigger an express Step Functions workflow
4️⃣ (Optionally) Add dynamic delay inside Lambda controlled by AppConfig
5️⃣ Step Function invokes an API Gateway HTTP proxy API
6️⃣ Invoke the external third-party asynchronous service API
7️⃣ Store the workflow’s task token and the received job ID in DynamoDB
8️⃣ Receive the completed job ID in a callback webhook endpoint
9️⃣ Transform the external callbacks with API Gateway
🔟 Use Lambda to poll the callback SQS
1️⃣1️⃣ Pass the job ID to the next step, and invoke a Step Function processor to fetch the job’s results

#design