You are using for sure agile methods to manage your infrastructure or deploy code on your application-systems and maybe running automatically patch-management on them.
AWS EC2-instances can be also automated and this can happen at the creation point of each single instance.
During the configure step of the launch of an EC2 instance, you can select the drop-down block(User Data) and put your bootstrapping-script into this field.
This code gets automatically executed only once during the provisioning process of the new instance.
This is can be a very simple bash script, which helps you to start an instance with the basic configuration.
Like a webserver which can be a part of a lodbalancing group:
#!/bin/bash yum update -y yum install httpd -y service httpd start chkconfig httpd on echo "<html><h1>welcome to web-instance01</h1></html>" > /var/www/html/index.html
There are no bootstrapping-limits, you can bootstrap everything and save your time and avoid manually steps.