It’s pretty easy to set up and configure a new AWS Lambda with the AWS Console, but if you’re iterating on some changes and need to redeploy a few times, the AWS CLI makes it pretty easy.
To create a new Lambda, assuming you have a .zip packaged up and ready to go:
aws lambda create-function --function-name example-lambda --zip-file fileb://example-lambda.zip --handler index.handler --runtime nodejs8.10 --role arn:aws:iam::role-id-here:role/lambda-role