Strictly looking at server uptime, yes, it's nearly 5x the cost of comparable t2 on-demand EC2 instances. That can be mitigated if you have spiky traffic where

Strictly looking at server uptime, yes, it's nearly 5x the cost of comparable t2 on-demand EC2 instances. That can be mitigated if you have spiky traffic where you'd need to turn on several EC2 instances for less than an hour but are stuck paying for the full hour, or if you can scale to zero for extended periods of time. You don't have the ability to serve concurrent requests from a single lambda worker, so if you're waiting for async IO then you're wasting money you wouldn't be wasting with EC2. -- For us lambda was prohibitively expensive at scale. I suspect a fair number of people reporting significant savings vs EC2 had over-provisioned instances.