Isn't most of the draw of Amazon Lambda that you can hook everything else into a simple api hosting service? I doubt there are any direct competitors, at least at that scale.
+1 one of the draws for Lambda is that it has easy integration with other AWS tools (Kinesis, DynamoDB, SNS, even CloudFormation) and is really low-cost since you only pay for execution time.
And Amazon API Gateway, potentially the request routing layer for a heterogenous set of Lamdba-backed endpoints. Seems like that may have been particularly a service jenkstom was referring to. https://aws.amazon.com/api-gateway/
Here is a discussion:
https://www.quora.com/Are-there-any-alternatives-to-Amazon-L...