📅 Date: Week 4 (Day 5) 🎯 Topic: EC2·Lambda·ECS deployment strategy integration + auto-rollback design + 12 scenario problems
Through Week 4, we've traveled three different worlds. The world of EC2 with physical instances, Lambda with function versions, ECS with container Task Sets. Though we use the same word "deployment," each world operates under entirely different physical laws.
In EC2 In-place deployment, rollback is "push old code again" — downtime occurs. In EC2 Blue/Green, rollback is "return ALB traffic to Blue ASG" — completed within a minute