# High-Level Architecture Diagram: Company Inc.

## Cloud Infrastructure (GCP + GKE)

```mermaid
flowchart TB
    subgraph Internet
        Users((Users))
    end

    subgraph GCP["Google Cloud Platform"]
        subgraph Projects["Project Structure"]
            Prod[company-inc-prod]
            Staging[company-inc-staging]
            Shared[company-inc-shared]
            Sandbox[company-inc-sandbox]
        end

        subgraph Edge["Edge / Networking"]
            LB[Cloud Load Balancer<br/>HTTPS · TLS termination]
            CDN[Cloud CDN<br/>Static Assets]
            NAT[Cloud NAT<br/>Egress]
        end

        subgraph VPC["VPC — Private Subnets"]
            subgraph GKE["GKE Autopilot Cluster"]
                Ingress[Ingress Controller]
                subgraph Workloads
                    API[Backend — Python / Flask<br/>HPA · 2–3 replicas]
                    SPA[Frontend — React SPA<br/>Nginx]
                end
                Redis[Redis — Memorystore<br/>Session / Cache]
                Monitoring[Prometheus + Grafana<br/>Observability]
            end
        end

        subgraph Managed["Managed Services"]
            Mongo[(MongoDB Atlas<br/>3-node Replica Set<br/>Private Endpoint)]
            Secrets[Secret Manager]
            Registry[Artifact Registry]
        end
    end

    subgraph CICD["CI / CD"]
        Git[Git Repository]
        Actions[Gitea / GitHub Actions<br/>Build · Test · Scan]
        Argo[ArgoCD / Flux<br/>GitOps Deploy]
    end

    Users --> LB
    Users --> CDN
    LB --> Ingress
    CDN --> SPA
    Ingress --> API
    Ingress --> SPA
    API --> Redis
    API --> Mongo
    API --> Secrets
    GKE --> Registry
    GKE --> NAT

    Git --> Actions
    Actions --> Registry
    Argo --> GKE
```

## CI / CD Pipeline

```mermaid
flowchart LR
    Dev[Developer] -->|push| Repo[Git Repo]
    Repo -->|webhook| CI[CI Pipeline<br/>lint · test · build]
    CI -->|push image| Registry[Artifact Registry]
    CI -->|update manifests| GitOps[GitOps Repo]
    GitOps -->|sync| Argo[ArgoCD / Flux]
    Argo -->|deploy| GKE[GKE Cluster]
```

## Network Security Layers

```mermaid
flowchart TD
    Internet((Internet)) --> FW[VPC Firewall<br/>Default deny]
    FW --> LB[Load Balancer<br/>HTTPS only]
    LB --> NP[K8s Network Policies]
    NP --> Pods[Application Pods<br/>Private IPs only]
    Pods --> PE[Private Endpoint<br/>MongoDB Atlas]
```