Review this architecture
A colleague sends you this diagram before a launch and asks whether it looks alright. Everything is present, everything is labelled, and the application works today.
Three things in it are wrong. None of them will fail during testing, which is what makes a review the only place they get caught.
Tap every component that is in the wrong place.
!Three components in this design are wrong, and none of them will fail a test.
Boundaries, outermost first: VPC: Internet gateway (on the VPC) Public subnet: Database (public subnet), Load balancer (public subnet) Private subnet: NAT gateway (private subnet), Access keys (on the instance) Outside every boundary: Internet This diagram draws no connections between its components.
Tap every component that is wrong.