How is/was AWS bootstrapped ?

AWS offers IaaS (infra as a service). When we consume AWS infra to deploy our services it makes use of AWS service to create and manage the infra upon which our code will run. How does AWS manage the infra for its own IaaS deployments, i.e, the classical chicken and egg problem: how was the first IaaS offering from AWS deployed and how was it used to manage other hw for the public cloud of AWS ? Right now, my guess is AWS is in a state where it can be self bootstrapped, i.e AWS can use itself to deploy its own services but that would not have been the case during the initial days of AWS. So what gives and how did AWS solve this problem ?