NetworkSecurity
Firewalls, WAF, security groups — controlling what traffic can reach what.
Why we need this / what value this brings
Network-level controls are a defense layer independent of application code — they stop attacks that never even reach your app logic.
When to use this
Whenever provisioning infrastructure with any internet-facing surface.
How to use or implement this
Default to deny-all, then explicitly allow only the traffic that's actually needed (see Networking/VPC-Subnetting for the layout this depends on).
Empty folder — drop notes, links, and findings here as you research.