Infrastructure as Code makes infrastructure changes reviewable and reproducible. Protect Terraform state, use locking, review plans, restrict permissions, and avoid exposing secrets in state. State maps declared resources to real infrastructure and is operationally sensitive.

Cloud networking includes VPCs, subnets, routes, security groups, private endpoints, NAT, and load balancers. Distinguish public ingress from private service/database paths, and define egress controls, DNS, certificates, and workload identity.

A service mesh can provide workload identity, mutual TLS, traffic policy, and telemetry through data-plane proxies and a control plane. It also adds configuration and debugging complexity. Do not enable mesh retries blindly; they can duplicate side effects or multiply traffic. Establish ownership for mesh policies and understand their interaction with application deadlines.