Is it possible to use SAM CLI (or any other tool known to mankind) to deploy a lambda function with defined triggers, memory and timeout limits set, etc. the way SAM CLI is able to do it using Cloud Formation (or even in a better way)?
Currently I'm using TravisCI to deploy my lambda functions, but that's really just a better zip uploader to AWS, as I can't define any triggers for the lambda function the way I can do it through SAM (Serverless Application Model).
I would look into leveraging AWS Code pipeline, Codebuild, Code deploy for you serverless functions CI/CD. Sam also has some awesome baked in tools for leveraging code deploy under the hood to enable things like weighted roll outs canary deploys etc.
https://github.com/aws-samples/aws-safe-lambda-deployments https://aws.amazon.com/blogs/compute/implementing-safe-aws-lambda-deployments-with-aws-codedeploy/
For specifying things like memory, triggers, timeouts this would all be done in cloudformation template as you mentioned and this is best practice.
Since asking the question I came across diferrent useful tools to deploy configured Lambda functions:
All-in-one development & monitoring of auto-scaling apps on AWS Lambda
Define cloud infrastructure using familiar programming languages