You will absolutely need to notify AWS to scale to "world changing" levels or take on "massive surges" without spewing errors. There literal limits that require

You will absolutely need to notify AWS to scale to "world changing" levels or take on "massive surges" without spewing errors. There literal limits that require filling out a web form and waiting to get your ticket administered. Then Lambda is backed by EC2, which itself has functional (Re: AWS has per-minute limits on how fast you can add concurrency) and physical (Re: AWS has finite compute and will tell you they would like advances on your "massive" compute needs -- you can't just get infinite cloud off the shelf).