I can empathize with the OP. Using Lambda in production still has some pretty rough edges. You basically have to use one of the deployment tools/frameworks out there[1]. There are also just certain things it won't do (someone else mentioned binary data). Learning some of the limits takes time and it is not always super clear.
But my personal experience says Lambda is ready for prime time. We use it in production. ~15 million API calls per day. Mostly user facing HTTP requests. Even with the rough edges I would prefer to use it for any new web development project. It feels like at least an order of magnitude reduction in risk/complexity of scaling and deploying code. Its not "zero" but that is huge for me and for my team. We spend more time shipping.
But my personal experience says Lambda is ready for prime time. We use it in production. ~15 million API calls per day. Mostly user facing HTTP requests. Even with the rough edges I would prefer to use it for any new web development project. It feels like at least an order of magnitude reduction in risk/complexity of scaling and deploying code. Its not "zero" but that is huge for me and for my team. We spend more time shipping.
[1]We wrote one: https://github.com/bustlelabs/shep but there are plenty of others mentioned in the comments.