* AWS Support Dependency. IMO way better to have amazon managing more but it still increases reliance on amazon and support tickets

* Limited set of input events available. For example it's difficult to use rabbitmq but lambda orchestrates batching and orchestration for SQS

I didn't really mention these because I think they are better than the alternatives :)

I would personally rather manage a bunch of small functions leveraging amazon's documentation, community, clear interfaces, and SDK, than a random OSS async worker framework or homegrown processing system.

Companies that have committed to AWS are already dependent on AWS support, I haven't really found an issue with being more dependent on AWS support :p

The limited set of events has also been a net positive. There are few clearly defined options. I have found the limited choices helps delivery and simplifies architecture; less discussion. Also once a company learns SQS and kinesis, that knowledge is applicable everywhere, since those are the constrained choices.

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I would love to hear any experiences where lambda was not a good fit, or did not work out