Architecture - Panglot Platform

Architectural Overview

The Panglot platform implements a layered architecture combining modern distributed systems patterns. Each layer serves a specific purpose while maintaining loose coupling and high cohesion.

C4 Model - Level 1: System Context

High-level view showing how external actors interact with the Panglot platform.

graph TB
    subgraph External["🌍 External Actors"]
        USER[End Users
Web/Mobile]
        PARTNER[Business Partners
API Integration]
        ADMIN[System Administrators]
    end

    subgraph System["🏗️ Panglot Platform"]
        PLATFORM[Microservices Platform
REST/gRPC/Events]
    end

    subgraph ExternalSystems["🔗 External Systems"]
        IDP[Identity Provider
OIDC/OAuth2]
        PSP[Payment Service Provider]
        MONITOR[Monitoring Systems
APM/SIEM]
    end

    USER -->|HTTPS/REST| PLATFORM
    PARTNER -->|HTTPS/REST| PLATFORM
    ADMIN -->|Management APIs| PLATFORM

    PLATFORM -->|Authentication| IDP
    PLATFORM -->|Payment Processing| PSP
    PLATFORM -->|Telemetry| MONITOR

    style External fill:#e3f2fd
    style System fill:#f3e5f5
    style ExternalSystems fill:#fff3e0

Key Principle

External actors interact exclusively through REST APIs over HTTPS. Internal gRPC communication remains encapsulated within the platform boundary.

C4 Model - Level 2: Containers

Detailed view of major platform components and their interactions.

graph TB
    subgraph Internet["🌐 Internet"]
        CLIENTS[Clients]
    end

    subgraph EdgeLayer["🚪 Edge Layer"]
        CDN[CDN
Static Content]
        GW[API Gateway
TLS, Auth, Rate Limit]
        BFF[BFF Web
REST to gRPC]
    end

    subgraph ServicePlane["⚙️ Service Plane - Kubernetes"]
        ORDERS[Orders Service
gRPC + PostgreSQL]
        PAYMENTS[Payments Service
gRPC + PostgreSQL]
        INVENTORY[Inventory Service
gRPC + PostgreSQL]
    end

    subgraph ServiceMesh["🔗 Service Mesh Layer"]
        MESH[Istio/Linkerd
mTLS, LB, Circuit Breaker]
    end

    subgraph EventPlane["📨 Event Plane"]
        KAFKA[Event Bus
Kafka/NATS]
        REGISTRY[Schema Registry
Event Schemas]
        DLQ[Dead Letter Queue
Failed Messages]
    end

    subgraph Platform["🛠️ Platform Services"]
        OTEL[OpenTelemetry
Collector]
        VAULT[Secrets Management
Vault/KMS]
        CONFIG[Config Server
Centralized Config]
    end

    CLIENTS -->|HTTPS| CDN
    CDN --> GW
    GW --> BFF

    BFF -->|gRPC| ORDERS
    BFF -->|gRPC| PAYMENTS
    BFF -->|gRPC| INVENTORY

    ORDERS -.->|through| MESH
    PAYMENTS -.->|through| MESH
    INVENTORY -.->|through| MESH

    ORDERS -->|Events| KAFKA
    PAYMENTS -->|Events| KAFKA
    INVENTORY -->|Events| KAFKA

    KAFKA <--> REGISTRY
    KAFKA --> DLQ

    ORDERS -.->|Telemetry| OTEL
    PAYMENTS -.->|Telemetry| OTEL
    INVENTORY -.->|Telemetry| OTEL

    ORDERS -.->|Secrets| VAULT
    PAYMENTS -.->|Secrets| VAULT
    INVENTORY -.->|Secrets| VAULT

    style EdgeLayer fill:#e3f2fd
    style ServicePlane fill:#f3e5f5
    style EventPlane fill:#fff3e0
    style Platform fill:#e8f5e9

C4 Model - Level 3: Components

Internal structure of a typical microservice showing layered architecture.

graph TB
    subgraph Service[Orders Service]
        subgraph API[API Layer]
            GRPC[gRPC Controller
Request Validation]
            INTER[Interceptors
Auth, Logging, Tracing]
        end

        subgraph Domain[Domain Layer]
            LOGIC[Business Logic
State Management]
            VALID[Domain Validators
Invariants]
            EVENTS[Domain Events
Event Sourcing]
        end

        subgraph Data[Data Layer]
            REPO[Repository
Data Access]
            OUTBOX[Outbox Pattern
Transactional Events]
            CACHE[Local Cache
Read Optimization]
        end

        subgraph Infrastructure[Infrastructure]
            DB[(PostgreSQL
Primary Store)]
            RELAY[Outbox Relay
Event Publisher]
        end
    end

    subgraph External[External Systems]
        MESH_IN[Service Mesh
Ingress]
        MESH_OUT[Service Mesh
Egress]
        EVENTBUS[Event Bus]
    end

    MESH_IN -->|Requests| GRPC
    GRPC --> INTER
    INTER --> LOGIC
    LOGIC --> VALID
    LOGIC --> REPO
    LOGIC --> OUTBOX

    REPO --> DB
    OUTBOX --> DB
    CACHE -.->|Read-through| REPO

    RELAY -->|Poll| DB
    RELAY -->|Publish| EVENTBUS

    LOGIC -->|Call other services| MESH_OUT

    style API fill:#e3f2fd
    style Domain fill:#f3e5f5
    style Data fill:#fff3e0
    style Infrastructure fill:#e8f5e9

Layer Responsibilities

Layer	Components	Responsibility
API Layer	gRPC Controllers, Interceptors	Request handling, validation, cross-cutting concerns
Domain Layer	Business Logic, Validators, Events	Core business rules, state transitions, domain events
Data Layer	Repositories, Outbox, Cache	Data persistence, transactional consistency
Infrastructure	Database, Event Relay	External dependencies, async event publishing

Contract-First Design

All interfaces are defined using Interface Definition Languages (IDL) before implementation.

graph LR
    subgraph Contracts["📋 Contract Definitions"]
        PROTO[Protocol Buffers
.proto files]
        OPENAPI[OpenAPI Specs
REST APIs]
        EVENTS[Event Schemas
JSON Schema/Avro]
    end

    subgraph Generation["⚙️ Code Generation"]
        PROTOC[protoc compiler]
        OPENAPI_GEN[OpenAPI Generator]
        SCHEMA_REG[Schema Registry]
    end

    subgraph Artifacts["📦 Generated Code"]
        GO_STUB[Go gRPC Stubs]
        REST_DOC[REST Documentation]
        VALIDATORS[Schema Validators]
    end

    subgraph Services["🔧 Services"]
        SVC1[Orders Service]
        SVC2[Payments Service]
        SVC3[Inventory Service]
    end

    PROTO --> PROTOC
    OPENAPI --> OPENAPI_GEN
    EVENTS --> SCHEMA_REG

    PROTOC --> GO_STUB
    OPENAPI_GEN --> REST_DOC
    SCHEMA_REG --> VALIDATORS

    GO_STUB --> SVC1
    GO_STUB --> SVC2
    GO_STUB --> SVC3

    style Contracts fill:#e3f2fd
    style Generation fill:#fff3e0
    style Artifacts fill:#f3e5f5
    style Services fill:#e8f5e9

Benefits of Contract-First

Type Safety: Compile-time verification of interface compatibility
Documentation: Contracts serve as living documentation
Multi-Language: Generate client/server code for multiple languages
Versioning: Explicit version management and backward compatibility
Parallel Development: Teams develop independently against contracts

Service Mesh Architecture

The service mesh provides network-level capabilities transparently to application services.

graph TB
    subgraph ControlPlane["🎛️ Control Plane"]
        PILOT[Pilot
Service Discovery]
        CITADEL[Citadel
Certificate Authority]
        GALLEY[Galley
Configuration]
    end

    subgraph DataPlane["📡 Data Plane"]
        subgraph Pod1["Pod: Orders Service"]
            APP1[Orders App]
            PROXY1[Envoy Sidecar]
        end

        subgraph Pod2["Pod: Payments Service"]
            APP2[Payments App]
            PROXY2[Envoy Sidecar]
        end

        subgraph Pod3["Pod: Inventory Service"]
            APP3[Inventory App]
            PROXY3[Envoy Sidecar]
        end
    end

    PILOT -.->|Config| PROXY1
    PILOT -.->|Config| PROXY2
    PILOT -.->|Config| PROXY3

    CITADEL -.->|Certs| PROXY1
    CITADEL -.->|Certs| PROXY2
    CITADEL -.->|Certs| PROXY3

    APP1 <-->|localhost| PROXY1
    APP2 <-->|localhost| PROXY2
    APP3 <-->|localhost| PROXY3

    PROXY1 <-->|mTLS| PROXY2
    PROXY2 <-->|mTLS| PROXY3
    PROXY1 <-->|mTLS| PROXY3

    style ControlPlane fill:#e3f2fd
    style DataPlane fill:#f3e5f5

Service Mesh Capabilities

Feature	Benefit	Implementation
Mutual TLS	Encrypted service-to-service communication	Automatic certificate rotation
Traffic Management	Canary deployments, A/B testing	Traffic splitting, routing rules
Observability	Automatic metrics and tracing	Prometheus metrics, Jaeger traces
Resilience	Failure recovery	Retries, timeouts, circuit breakers

Event-Driven Architecture

Events enable asynchronous communication and temporal decoupling between services.

graph TB
    subgraph Publishers["📤 Event Publishers"]
        SVC1[Orders Service
Outbox Pattern]
        SVC2[Payments Service
Outbox Pattern]
        SVC3[Inventory Service
Outbox Pattern]
    end

    subgraph EventBus["📨 Event Bus - Kafka"]
        TOPIC1[orders.events
Partitioned by order_id]
        TOPIC2[payments.events
Partitioned by payment_id]
        TOPIC3[inventory.events
Partitioned by product_id]
    end

    subgraph Registry["📋 Schema Registry"]
        SCHEMA[Event Schemas
Version Control]
        COMPAT[Compatibility Checks
Forward/Backward]
    end

    subgraph Subscribers["📥 Event Subscribers"]
        SUB1[Fulfillment Service]
        SUB2[Analytics Service]
        SUB3[Notification Service]
        SUB4[Saga Orchestrator]
    end

    SVC1 -->|Publish| TOPIC1
    SVC2 -->|Publish| TOPIC2
    SVC3 -->|Publish| TOPIC3

    TOPIC1 -.->|Validate| SCHEMA
    TOPIC2 -.->|Validate| SCHEMA
    TOPIC3 -.->|Validate| SCHEMA

    TOPIC1 --> SUB1
    TOPIC1 --> SUB4
    TOPIC2 --> SUB2
    TOPIC2 --> SUB4
    TOPIC3 --> SUB3
    TOPIC3 --> SUB4

    style Publishers fill:#e3f2fd
    style EventBus fill:#fff3e0
    style Registry fill:#f3e5f5
    style Subscribers fill:#e8f5e9

Event Design Principles

CloudEvents Standard: All events follow CloudEvents specification
Idempotent Consumers: Events can be processed multiple times safely
Event Versioning: Schema evolution without breaking consumers
Partitioning: Ordered processing per entity (order, payment, etc.)
Dead Letter Queue: Failed messages isolated for investigation

Data Management

Each service owns its database, ensuring autonomy and preventing tight coupling.

graph TB
    subgraph Service1["Orders Service"]
        APP1[Application]
        REPO1[Repository]
        OUTBOX1[Outbox Table]
    end

    subgraph Service2["Payments Service"]
        APP2[Application]
        REPO2[Repository]
        OUTBOX2[Outbox Table]
    end

    subgraph Service3["Inventory Service"]
        APP3[Application]
        REPO3[Repository]
        OUTBOX3[Outbox Table]
    end

    DB1[(Orders DB
PostgreSQL)]
    DB2[(Payments DB
PostgreSQL)]
    DB3[(Inventory DB
PostgreSQL)]

    APP1 --> REPO1
    REPO1 --> DB1
    OUTBOX1 --> DB1

    APP2 --> REPO2
    REPO2 --> DB2
    OUTBOX2 --> DB2

    APP3 --> REPO3
    REPO3 --> DB3
    OUTBOX3 --> DB3

    OUTBOX1 -.->|Relay| KAFKA[Event Bus]
    OUTBOX2 -.->|Relay| KAFKA
    OUTBOX3 -.->|Relay| KAFKA

    style Service1 fill:#e3f2fd
    style Service2 fill:#f3e5f5
    style Service3 fill:#fff3e0

Database per Service Pattern

Services never directly access another service's database. All inter-service communication occurs through APIs (gRPC) or events. This ensures loose coupling and independent evolution.

Observability Stack

Comprehensive observability using the three pillars: traces, metrics, and logs.

graph TB
    subgraph Services["🔧 Services"]
        SVC[Microservices
with OpenTelemetry SDK]
    end

    subgraph Collection["📊 Collection Layer"]
        OTEL[OpenTelemetry
Collector]
    end

    subgraph Storage["💾 Storage Backends"]
        JAEGER[Jaeger
Distributed Tracing]
        PROM[Prometheus
Metrics TSDB]
        LOKI[Loki
Log Aggregation]
    end

    subgraph Visualization["📈 Visualization"]
        GRAFANA[Grafana
Unified Dashboard]
        ALERT[Alert Manager
Notifications]
    end

    SVC -->|Traces| OTEL
    SVC -->|Metrics| OTEL
    SVC -->|Logs| OTEL

    OTEL -->|Export| JAEGER
    OTEL -->|Export| PROM
    OTEL -->|Export| LOKI

    JAEGER --> GRAFANA
    PROM --> GRAFANA
    LOKI --> GRAFANA

    PROM --> ALERT
    LOKI --> ALERT

    style Services fill:#e3f2fd
    style Collection fill:#fff3e0
    style Storage fill:#f3e5f5
    style Visualization fill:#e8f5e9

Observability Signals

Signal	Technology	Use Case
Traces	Jaeger	Request flow analysis, latency breakdown
Metrics	Prometheus	Performance monitoring, SLI/SLO tracking
Logs	Loki	Debugging, audit trails, error analysis
Correlation	Trace ID	Link traces, metrics, and logs together

Deployment Architecture

Kubernetes-native deployment with GitOps principles and progressive delivery.

graph LR
    subgraph Source["📝 Source Control"]
        GIT[Git Repository
Contracts + Code]
    end

    subgraph CI["🔨 CI Pipeline"]
        BUILD[Build & Test]
        GEN[Generate Code]
        IMAGE[Container Image]
    end

    subgraph CD["🚀 CD Pipeline"]
        ARGOCD[ArgoCD
GitOps]
        FLUX[Flux
Reconciliation]
    end

    subgraph Cluster["☸️ Kubernetes Cluster"]
        DEV[Dev Namespace]
        STAGING[Staging Namespace]
        PROD[Production Namespace]
    end

    GIT --> BUILD
    BUILD --> GEN
    GEN --> IMAGE
    IMAGE --> ARGOCD
    ARGOCD --> FLUX
    FLUX --> DEV
    FLUX --> STAGING
    FLUX --> PROD

    style Source fill:#e3f2fd
    style CI fill:#fff3e0
    style CD fill:#f3e5f5
    style Cluster fill:#e8f5e9

Network Architecture Design

The Panglot platform supports multiple deployment topologies to meet diverse organizational requirements, from single cloud deployments to complex multi-site hybrid architectures.

Deployment Topologies

1. Cloud-Native Deployment

Single cloud provider deployment with full managed services integration.

graph TB
    subgraph Internet[Internet]
        USERS[End Users]
    end

    subgraph CloudProvider[Cloud Provider - AWS/Azure/GCP]
        subgraph EdgeServices[Edge Services]
            CDN[CDN
CloudFront/CloudFlare]
            WAF[WAF
DDoS Protection]
            LB[Load Balancer
ALB/NLB]
        end

        subgraph Region1[Region: us-east-1]
            subgraph AZ1[Availability Zone A]
                K8S_AZ1[Kubernetes Nodes]
                DB_AZ1[(Database Primary)]
            end

            subgraph AZ2[Availability Zone B]
                K8S_AZ2[Kubernetes Nodes]
                DB_AZ2[(Database Replica)]
            end

            subgraph AZ3[Availability Zone C]
                K8S_AZ3[Kubernetes Nodes]
                DB_AZ3[(Database Replica)]
            end
        end

        subgraph ManagedServices[Managed Services]
            KAFKA[Managed Kafka
MSK/Event Hubs]
            CACHE[Managed Cache
ElastiCache/Redis]
            SECRETS[Secrets Manager
AWS Secrets/Key Vault]
        end
    end

    USERS --> CDN
    CDN --> WAF
    WAF --> LB
    LB --> K8S_AZ1
    LB --> K8S_AZ2
    LB --> K8S_AZ3

    K8S_AZ1 --> DB_AZ1
    K8S_AZ2 --> DB_AZ1
    K8S_AZ3 --> DB_AZ1

    DB_AZ1 -.->|Replication| DB_AZ2
    DB_AZ1 -.->|Replication| DB_AZ3

    K8S_AZ1 --> KAFKA
    K8S_AZ2 --> KAFKA
    K8S_AZ3 --> KAFKA

    style Internet fill:#e3f2fd
    style EdgeServices fill:#fff3e0
    style Region1 fill:#f3e5f5
    style ManagedServices fill:#e8f5e9

✅ Cloud-Native Benefits

Full managed services (databases, message brokers, caching)
Auto-scaling and load balancing
Built-in high availability across availability zones
Pay-as-you-go pricing model

2. On-Premises Deployment

Self-hosted infrastructure for organizations with strict data residency requirements.

graph TB
    subgraph Corporate[Corporate Network]
        USERS[Internal Users]
    end

    subgraph DMZ[DMZ Zone]
        FW[Firewall]
        PROXY[Reverse Proxy
Nginx/HAProxy]
    end

    subgraph DataCenter[On-Premises Data Center]
        subgraph Compute[Compute Cluster]
            K8S1[Kubernetes Master 1]
            K8S2[Kubernetes Master 2]
            K8S3[Kubernetes Master 3]
            NODES[Worker Nodes
Bare Metal/VMs]
        end

        subgraph Storage[Storage Layer]
            CEPH[Distributed Storage
Ceph/GlusterFS]
            NAS[NAS/SAN
Backup Storage]
        end

        subgraph Data[Data Layer]
            PG_PRIMARY[(PostgreSQL
Primary)]
            PG_STANDBY[(PostgreSQL
Standby)]
            KAFKA_CLUSTER[Kafka Cluster
3 Brokers]
        end

        subgraph Network[Network Infrastructure]
            SWITCH[Core Switch]
            ROUTER[Router]
        end
    end

    USERS --> FW
    FW --> PROXY
    PROXY --> K8S1
    PROXY --> K8S2
    PROXY --> K8S3

    K8S1 --> NODES
    K8S2 --> NODES
    K8S3 --> NODES

    NODES --> PG_PRIMARY
    PG_PRIMARY -.->|Streaming Replication| PG_STANDBY

    NODES --> KAFKA_CLUSTER
    NODES --> CEPH

    CEPH -.->|Backup| NAS

    style DMZ fill:#fff3e0
    style Compute fill:#e3f2fd
    style Storage fill:#f3e5f5
    style Data fill:#e8f5e9

3. Hybrid Cloud Architecture

Combination of on-premises and cloud infrastructure for flexibility and gradual migration.

graph TB
    subgraph OnPrem[On-Premises Data Center]
        LEGACY[Legacy Systems
Core Banking]
        K8S_ONPREM[Kubernetes Cluster
Sensitive Workloads]
        DB_ONPREM[(Primary Database
Customer Data)]
    end

    subgraph VPN[Secure Connection]
        SITE2SITE[Site-to-Site VPN
IPSec Tunnel]
        DIRECT[Direct Connect
AWS/Azure ExpressRoute]
    end

    subgraph Cloud[Public Cloud]
        K8S_CLOUD[Kubernetes Cluster
Scalable Workloads]
        API_GW[API Gateway
External Traffic]
        CACHE_CLOUD[Cache Layer
Read Replicas]
    end

    subgraph Integration[Integration Layer]
        EVENT_BRIDGE[Event Bridge
Cross-Environment Events]
        DATA_SYNC[Data Sync
CDC Pipeline]
    end

    LEGACY --> K8S_ONPREM
    K8S_ONPREM --> DB_ONPREM

    K8S_ONPREM <-->|Encrypted| SITE2SITE
    K8S_ONPREM <-->|High Bandwidth| DIRECT

    SITE2SITE <--> K8S_CLOUD
    DIRECT <--> K8S_CLOUD

    K8S_CLOUD --> API_GW
    K8S_CLOUD --> CACHE_CLOUD

    DB_ONPREM -.->|Replication| DATA_SYNC
    DATA_SYNC -.-> CACHE_CLOUD

    K8S_ONPREM --> EVENT_BRIDGE
    K8S_CLOUD --> EVENT_BRIDGE

    style OnPrem fill:#f3e5f5
    style VPN fill:#fff3e0
    style Cloud fill:#e3f2fd
    style Integration fill:#e8f5e9

Hybrid Cloud Use Cases

Compliance: Keep sensitive data on-premises while using cloud for processing
Burst Scaling: Handle peak loads in cloud while maintaining baseline on-prem
Migration: Gradual transition from on-premises to cloud
Disaster Recovery: Cloud as backup site for on-premises workloads

4. Multi-Site Deployment

Geographically distributed deployments for global reach and disaster recovery.

graph TB
    subgraph Users[Global Users]
        US[US Users]
        EU[EU Users]
        ASIA[Asia Users]
    end

    subgraph DNS[Global DNS]
        ROUTE53[Route53/CloudFlare
Geo-Routing]
    end

    subgraph Region_US[US Region - us-east-1]
        LB_US[Load Balancer]
        K8S_US[Kubernetes Cluster]
        DB_US[(Database Primary)]
        KAFKA_US[Kafka Cluster]
    end

    subgraph Region_EU[EU Region - eu-west-1]
        LB_EU[Load Balancer]
        K8S_EU[Kubernetes Cluster]
        DB_EU[(Database Primary)]
        KAFKA_EU[Kafka Cluster]
    end

    subgraph Region_ASIA[Asia Region - ap-southeast-1]
        LB_ASIA[Load Balancer]
        K8S_ASIA[Kubernetes Cluster]
        DB_ASIA[(Database Primary)]
        KAFKA_ASIA[Kafka Cluster]
    end

    subgraph Replication[Cross-Region Replication]
        DB_SYNC[Database Replication
CDC/Async]
        EVENT_SYNC[Event Mirroring
Kafka MirrorMaker]
    end

    US --> ROUTE53
    EU --> ROUTE53
    ASIA --> ROUTE53

    ROUTE53 -->|Geo-DNS| LB_US
    ROUTE53 -->|Geo-DNS| LB_EU
    ROUTE53 -->|Geo-DNS| LB_ASIA

    LB_US --> K8S_US
    LB_EU --> K8S_EU
    LB_ASIA --> K8S_ASIA

    K8S_US --> DB_US
    K8S_EU --> DB_EU
    K8S_ASIA --> DB_ASIA

    K8S_US --> KAFKA_US
    K8S_EU --> KAFKA_EU
    K8S_ASIA --> KAFKA_ASIA

    DB_US <-.->|Async| DB_SYNC
    DB_EU <-.->|Async| DB_SYNC
    DB_ASIA <-.->|Async| DB_SYNC

    KAFKA_US <-.-> EVENT_SYNC
    KAFKA_EU <-.-> EVENT_SYNC
    KAFKA_ASIA <-.-> EVENT_SYNC

    style Users fill:#e3f2fd
    style Region_US fill:#f3e5f5
    style Region_EU fill:#fff3e0
    style Region_ASIA fill:#e8f5e9
    style Replication fill:#e3f2fd

5. Service Federation

Multiple independent Panglot deployments federated for inter-organization collaboration.

graph TB
    subgraph Org1[Organization A - Bank]
        K8S_A[Panglot Cluster A]
        API_A[Public API Gateway]
        SERVICES_A[Core Banking Services]
    end

    subgraph Org2[Organization B - Payment Provider]
        K8S_B[Panglot Cluster B]
        API_B[Public API Gateway]
        SERVICES_B[Payment Services]
    end

    subgraph Org3[Organization C - Analytics]
        K8S_C[Panglot Cluster C]
        API_C[Public API Gateway]
        SERVICES_C[Analytics Services]
    end

    subgraph Federation[Federation Layer]
        REGISTRY[Service Registry
Consul/Eureka]
        AUTH[Federated Auth
OAuth2/OIDC]
        GATEWAY[API Federation Gateway]
    end

    subgraph Events[Event Federation]
        EVENT_HUB[Event Hub
Cross-Org Events]
        SCHEMA_REGISTRY[Schema Registry
Contract Validation]
    end

    K8S_A --> API_A
    K8S_B --> API_B
    K8S_C --> API_C

    API_A --> GATEWAY
    API_B --> GATEWAY
    API_C --> GATEWAY

    GATEWAY --> REGISTRY
    GATEWAY --> AUTH

    SERVICES_A --> EVENT_HUB
    SERVICES_B --> EVENT_HUB
    SERVICES_C --> EVENT_HUB

    EVENT_HUB --> SCHEMA_REGISTRY

    style Org1 fill:#e3f2fd
    style Org2 fill:#f3e5f5
    style Org3 fill:#fff3e0
    style Federation fill:#e8f5e9

⚠️ Federation Challenges

Service discovery across organizational boundaries
Unified authentication and authorization
Data privacy and compliance across jurisdictions
Schema evolution and backward compatibility
Monitoring and debugging distributed traces

Network Security Zones

Security segmentation across all deployment topologies.

graph TB
    subgraph Internet[Internet Zone]
        PUBLIC[Public Internet]
    end

    subgraph DMZ[DMZ - Demilitarized Zone]
        WAF[WAF/IDS/IPS]
        PROXY[Reverse Proxy]
    end

    subgraph AppZone[Application Zone]
        API[API Gateway]
        BFF[BFF Services]
        MESH[Service Mesh]
    end

    subgraph ServiceZone[Service Zone]
        ORDERS[Orders Service]
        PAYMENTS[Payments Service]
        INVENTORY[Inventory Service]
    end

    subgraph DataZone[Data Zone]
        DB[(Databases)]
        CACHE[(Cache)]
        QUEUE[Message Queue]
    end

    subgraph MgmtZone[Management Zone]
        MONITOR[Monitoring]
        LOGGING[Logging]
        DEPLOY[CI/CD]
    end

    PUBLIC -->|HTTPS:443| WAF
    WAF -->|Filtered| PROXY
    PROXY -->|TLS| API

    API --> BFF
    BFF --> MESH

    MESH -->|mTLS| ORDERS
    MESH -->|mTLS| PAYMENTS
    MESH -->|mTLS| INVENTORY

    ORDERS -->|Encrypted| DB
    PAYMENTS -->|Encrypted| DB
    INVENTORY -->|Encrypted| DB

    ORDERS --> QUEUE
    PAYMENTS --> QUEUE
    INVENTORY --> QUEUE

    ORDERS -.->|Metrics| MONITOR
    PAYMENTS -.->|Metrics| MONITOR
    INVENTORY -.->|Metrics| MONITOR

    MgmtZone -.->|Management| ServiceZone

    style Internet fill:#f44336,color:#fff
    style DMZ fill:#ff9800,color:#fff
    style AppZone fill:#fff3e0
    style ServiceZone fill:#e3f2fd
    style DataZone fill:#f3e5f5
    style MgmtZone fill:#e8f5e9

Network Topology Comparison

Topology	Latency	Cost	Complexity	Best For
Cloud-Native	Low (single region)	Medium	Low	Startups, SaaS, rapid scaling
On-Premises	Very Low (local)	High (CapEx)	High	Banking, healthcare, compliance
Hybrid	Medium	Medium-High	Very High	Enterprises, gradual migration
Multi-Site	Varies by region	High	Very High	Global apps, DR requirements
Federation	High (cross-org)	Medium per org	Extreme	B2B marketplaces, consortiums

Network Performance Optimization

🌐 Content Delivery Network (CDN)

Static assets cached at edge locations worldwide, reducing latency and bandwidth costs. API Gateway responses can be cached for GET requests with appropriate TTL.

🔄 Traffic Management

Intelligent routing based on geography, load, health checks, and custom rules. Supports canary deployments, A/B testing, and gradual rollouts.

📊 Regional Failover

Automatic failover to healthy regions when primary region experiences issues. Health checks at multiple levels: DNS, load balancer, service mesh.

🔐 Private Connectivity

Direct Connect, ExpressRoute, or Cloud Interconnect for dedicated, low-latency connections between cloud providers and on-premises infrastructure.