I have published an InfoQ news post about the AWS team's serverless solution for orchestrating high-volume, short duration microservices behind Amazon API Gateway:
Amazon Web Services (AWS) recently announced that AWS Step Functions supports synchronous Express workflows to "easily build web-based applications and orchestrate high-volume, short-duration microservices". Express workflows, a cost-effective, high-performance workflow type with a runtime of up to five minutes, can now be synchronously invoked from Amazon API Gateway or directly via the API.
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Continue reading the full post in AWS Step Functions Gains Synchronous Express Workflows.