Cloud Migration Security

200-year-old bank moving to the cloud. Legacy security team used to defending a perimeter. Developers used to locked-down environments where security said no to everything. Recipe for disaster. Cloud security isn't about building walls. It's about building guardrails that let people move fast safely. Get that wrong and you either block innovation or you get breached. I designed the security architecture for their GCP migration. Not just technical controls, but the entire operatingmodel. How teams would work, who could do what, what was automated versus what needed approval. Built landing zones with security baked in. Projects came pre-configured with logging, encryption, network controls, IAM policies. Developers got environments where the secure way was the easy way. Implemented policy-as-code so security requirements lived in git alongside infrastructure code. Changes were reviewed, versioned, and auditable. No more spreadsheets of security requirements nobody read. Created self-service security for developers. Want to deploy something? System automatically scans it, checks policy, and either approves it or tells you exactly what's wrong. Most requests approved automatically within minutes. Only edge cases needed human review. The cultural piece was harder than the technical piece. Spent time embedded with dev teams showing them how cloud-native security actually enabled velocity. Automated secrets management instead of hardcoded credentials. Infrastructure-as-code instead of manual configuration. Security as automated tests instead of manual reviews. Migrated 50 applications to GCP in 8 months with zero security incidents. Faster than planned because security stopped being a bottleneck. Developers started requesting cloud migrations because it was easier than dealing with legacy infrastructure. Passed their first cloud security audit with zero findings. Regulators were initially skeptical about cloud banking but the automated controls and audit trails were actually better than their legacy environment.