Zero-Trust Architecture
Never implicitly trust a request because of where it came from — verify identity and authorization on every single call.
Traditional network security drew a hard perimeter — trusted inside, untrusted outside — and assumed anything already inside the network was safe. Zero trust drops that assumption entirely: every request is authenticated and authorized on its own merits regardless of network location, because a single compromised internal service or laptop is enough to defeat a perimeter-only model. In practice this means mTLS between services and short-lived, narrowly-scoped credentials rather than a flat trusted internal network.
Worked example: never trust based on network location — every request is authenticated and authorized as if from the open internet, even inside the perimeter, so a breached internal host cannot move laterally for free. Gotcha: it replaces ‘inside the VPN = trusted’ with per-request identity (mTLS, short-lived tokens, device posture), making the identity and policy layer critical infrastructure; get its availability wrong and you lock out your own services.