Design and operate a production-grade Google Cloud platform for a global SaaS solution with deep hands-on ownership of Kubernetes, CI/CD, service mesh, and auditability. Deploy and manage regional GKE clusters (e.g., primary in me-central1/Riyadh), implement secure multi-environment landing zones, and build reusable Infrastructure-as-Code with automated, auditable provisioning. Build CI/CD pipelines using Cloud Build and/or GitHub Actions to containerize and deliver Python backend and Angular frontend services, publish Docker images, and deploy via Helm charts with tenant-specific configuration. Implement advanced deployment strategies on GKE using Istio service mesh, including header-based canary releases and tenant-aware traffic routing (e.g., X-Tenant-ID). Enable global scalability, multi-tenant isolation, observability, and resilience, and implement system-wide immutable audit logging/ledger mechanisms to record and trace all platform and configuration changes.