Cons of AWS Lambda
Functions timeout after 15 minutes, so containers are not ideal for running large workloads.
Your AWS Lambda bill can spike if you don't know how to optimize costs.
There's a limit of 250MB on the size of your Lambda code. ...
You can only run a maximum of 1000 concurrent requests.
Cold Starts
https://cloudinfrastructureservices.co.uk/aws-lambda-vs-containers-whats-the-difference/