AWS Lambda is great for inconsistent atomic workloads. However, I had a fairly disappointing experience with Lamda when I tested it just last week. For example

AWS Lambda is great for inconsistent atomic workloads. However, I had a fairly disappointing experience with Lamda when I tested it just last week. For example, you cannot send dynamic response headers using the AWS API Gateway (the complementary service to expose HTTP endpoints). In my case I wanted to change the mime-type depending on JSON vs JSONP response. It's also not possible to connect Lambda directly to ElastiCache and mostly you are expected to work with S3 or DynamoDB (Amazon's proprietary JSON store and what was mostly responsible for the data outage recently in US East). ElastiCache would allow easy persistence which is why it's surprising it can't be connected to given that it's an AWS service (you can connect to it by creating an EC2 proxy but that would defeat the purpose of a serverless architecture). Some other oddities were sniffing the response body to set HTTP headers as opposed to just allowing your Lambda function to set the HTTP header directly or parsing the JSON response as opposed to doing a regex match.