graph TB subgraph CF["☁️ Cloudflare Edge
- DNS, WAF, CDN"] DNS["DNS Management"] WAF["WAF Protection"] CDN["Static Assets Cache"] SSL["SSL/TLS Encryption"] end subgraph CFW["☁️ Cloudflare Workers
- Edge Computing"] RateLimit["Rate Limiter"] Validation["Request Validation"] end subgraph Pages["📱 Frontend"] SPA["Nuxt.js SPA
Vue Components
PWA"] end subgraph Backend["🖥️ Backend Servers
zoo-backend (4vCPU, 8GB)"] Nginx["Nginx
Load Balancer"] API1["FastAPI Replica 1"] API2["FastAPI Replica 2"] API3["FastAPI Replica 3"] end subgraph Database["🗄️ Database
zoo-database (2vCPU, 4GB)"] PgBouncer["PgBouncer"] PostgreSQL["PostgreSQL 15"] end subgraph Cache["⚡ Redis 7"] CacheLayer["Distributed Cache"] QueueLayer["Task Queue"] end subgraph Workers["🔄 Celery Workers"] PayrollWorker["Payroll Calculator"] ReportWorker["Report Generator"] NotifWorker["Notification Sender"] end subgraph Storage["☁️ DO Spaces S3"] Docs["Documents"] Exports["Exports"] Backups["Backups"] end subgraph Observability["📊 Monitoring Stack"] Grafana["Grafana"] Loki["Loki Logs"] Mimir["Metrics"] end CF -->|HTTPS| CFW CFW -->|Forward| Pages CFW -->|Forward| Nginx Pages -->|API Calls| Nginx Nginx -->|LB| API1 Nginx -->|LB| API2 Nginx -->|LB| API3 API1 --> PgBouncer API2 --> PgBouncer API3 --> PgBouncer PgBouncer --> PostgreSQL API1 --> Cache API2 --> Cache API3 --> Cache Cache --> Workers Workers --> Storage API1 --> Observability API2 --> Observability API3 --> Observability style CF fill:#3b82f6,color:#fff style CFW fill:#06b6d4,color:#fff style Backend fill:#8b5cf6,color:#fff style Database fill:#ec4899,color:#fff style Cache fill:#f59e0b,color:#fff style Workers fill:#10b981,color:#fff

graph TD AUTH["🔐 auth
Authentication
Authorization
(Foundation)"] ORG["🏢 org
Organization
Structure"] ORG -->|depends| AUTH EMP["👤 employee
Employee
Management"] EMP -->|depends| AUTH EMP -->|depends| ORG ATT["📍 attendance
Attendance &
Presence"] ATT -->|depends| AUTH ATT -->|depends| EMP LEA["📅 leave
Leave & Time Off"] LEA -->|depends| AUTH LEA -->|depends| EMP LEA -->|depends| ORG BEN["💳 benefits
Benefits &
Allowances"] BEN -->|depends| AUTH BEN -->|depends| EMP BEN -->|depends| ORG PAY["💰 payroll
Payroll &
Compensation"] PAY -->|depends| AUTH PAY -->|depends| EMP PAY -->|depends| ATT PAY -->|depends| LEA PAY -->|depends| BEN PERF["⭐ performance
Performance
Management"] PERF -->|depends| AUTH PERF -->|depends| EMP PERF -->|depends| ORG TAL["🎯 talent
Talent
Management"] TAL -->|depends| AUTH TAL -->|depends| EMP TAL -->|depends| PERF LEARN["📚 learning
Learning &
Development"] LEARN -->|depends| AUTH LEARN -->|depends| EMP LEARN -->|depends| TAL KNOW["📖 knowledge
Knowledge Base"] KNOW -->|depends| AUTH KNOW -->|depends| ORG NOTIF["🔔 notification
(Cross-cutting)"] NOTIF -->|depends| AUTH NOTIF -.->|notifies| EMP NOTIF -.->|notifies| LEA NOTIF -.->|notifies| PAY NOTIF -.->|notifies| PERF REPORT["📊 report
(Read-only)
Reporting"] REPORT -->|reads| AUTH REPORT -->|reads| EMP REPORT -->|reads| ATT REPORT -->|reads| LEA REPORT -->|reads| PAY WF["⚙️ workflow
(Cross-cutting)
Workflow Engine"] WF -->|depends| AUTH WF -->|depends| ORG WF -.->|orchestrates| LEA WF -.->|orchestrates| PAY WF -.->|orchestrates| PERF style AUTH fill:#ff9999,color:#000 style NOTIF fill:#ffcc99,color:#000 style REPORT fill:#99ccff,color:#000 style WF fill:#99ff99,color:#000 style PAY fill:#ff99cc,color:#000

graph TB subgraph Global["🌍 Global"] CF_EDGE["☁️ Cloudflare Edge
Singapore
DNS, WAF, CDN"] end subgraph DO_SG["🏢 Digital Ocean - Singapore Region"] subgraph VPC["🔐 Private VPC
172.16.0.0/12"] subgraph BACKEND_NET["Backend Network"] BE_LB["🔀 Load Balancer
Floating IP
165.232.xxx.xxx"] BE_D1["zoo-backend-1
4 vCPU, 8GB RAM
$48/month
Primary"] BE_D2["zoo-backend-2
4 vCPU, 8GB RAM
$48/month
Standby"] end subgraph DB_NET["Database Network"] DB_LB["🔀 DB Failover
Private IP
172.16.1.10"] DB_PRIMARY["zoo-database
2 vCPU, 4GB RAM
$28/month
PostgreSQL 15"] DB_REPLICA["zoo-database-replica
2 vCPU, 4GB RAM
$28/month
Read Replica"] end subgraph CACHE_NET["Cache Network"] REDIS["Redis 7
Managed
1GB Memory
$12/month"] end subgraph OBS_NET["Observability Network"] OBS["zoo-observability
2 vCPU, 4GB RAM
$28/month
Grafana, Loki, Mimir"] end end subgraph STORAGE["☁️ Storage"] S3["DO Spaces S3
Object Storage
$5/month"] end end CF_EDGE -->|HTTPS/443| BE_LB BE_LB -->|LB| BE_D1 BE_LB -->|LB| BE_D2 BE_D1 -->|Private| DB_LB BE_D2 -->|Private| DB_LB DB_LB -->|Primary| DB_PRIMARY DB_LB -->|Replica| DB_REPLICA BE_D1 -->|Cache| REDIS BE_D2 -->|Cache| REDIS BE_D1 -->|Logs| OBS BE_D2 -->|Logs| OBS BE_D1 -->|Store| S3 BE_D2 -->|Store| S3 style CF_EDGE fill:#3b82f6,color:#fff style VPC fill:#f3f4f6,stroke:#9ca3af,stroke-width:2px style STORAGE fill:#f3f4f6,stroke:#9ca3af,stroke-width:2px

graph LR subgraph Source["📝 Source Control"] REPO["GitHub Repository
zoo-hris"] end subgraph Trigger["🎯 Trigger"] PUSH["Push to main
or PR to main"] end subgraph Testing["✅ Testing Phase"] LINT["Linting
Black, Ruff
Pylint"] UNIT["Unit Tests
pytest
95% coverage"] INTEG["Integration Tests
Test DB, Redis"] BUILD["Build Docker
Image"] end subgraph Registry["📦 Container Registry"] REGISTRY["DO Container Registry
zoo-hris/backend:vX.X.X"] end subgraph Deployment["🚀 Deployment"] STAGING["Deploy Staging
zoo-backend-staging
Smoke Tests"] PROD["Deploy Production
Blue-Green
Gradual Rollout"] end subgraph Monitor["📊 Monitoring"] CHECK["Health Checks
Error Rate, Performance"] ROLLBACK["Auto Rollback
on Failure"] end REPO -->|Event| Trigger Trigger -->|Webhook| LINT LINT -->|✓| UNIT UNIT -->|✓| INTEG INTEG -->|✓| BUILD BUILD -->|Push| REGISTRY REGISTRY -->|Deploy| STAGING STAGING -->|Manual| PROD PROD -->|Continuous| CHECK CHECK -->|Failure| ROLLBACK CHECK -->|Success| SUCCESS["✅ Live"] ROLLBACK -->|Revert| REGISTRY style LINT fill:#86efac,color:#000 style UNIT fill:#86efac,color:#000 style INTEG fill:#86efac,color:#000 style BUILD fill:#86efac,color:#000 style SUCCESS fill:#86efac,color:#000 style ROLLBACK fill:#fca5a5,color:#000

sequenceDiagram participant EMP as Employee
พนักงาน participant HRIS as HRIS System participant NOTIF as Notification
Service participant MGR as Manager
หัวหน้า participant DB as Database EMP->>HRIS: 1. Submit Leave Request
(Dates, Reason, Type) activate HRIS HRIS->>DB: 2. Validate Leave Balance DB-->>HRIS: ✓ Balance Available HRIS->>DB: 3. Create Request
(Status: PENDING) DB-->>HRIS: Request ID: LR-2024-001 HRIS->>NOTIF: 4. Notify Manager
(LINE, Email) activate NOTIF NOTIF-->>MGR: New Leave Request
for Approval deactivate NOTIF MGR->>HRIS: 5. Review & Approve activate HRIS HRIS->>DB: 6. Update Status
(Status: APPROVED) DB-->>HRIS: Updated HRIS->>DB: 7. Deduct Balance
(Balance - Days) DB-->>HRIS: New Balance: 15 days HRIS->>DB: 8. Update Calendar
(Mark dates as OFF) DB-->>HRIS: Calendar Updated HRIS->>NOTIF: 9. Notify Employee
(Approval + New Balance) activate NOTIF NOTIF-->>EMP: Leave Approved✓
New Balance: 15 days deactivate NOTIF deactivate HRIS EMP->>HRIS: 10. View Updated Balance
& Calendar

sequenceDiagram participant USER as User
Browser participant PAGES as Frontend
Cloudflare Pages participant LOGTO as Logto Auth
Server participant API as HRIS API
Backend participant DB as Database USER->>PAGES: 1. Visit www.zoo-hris.com PAGES-->>USER: 2. Load Login Page USER->>PAGES: 3. Click Login Button PAGES->>LOGTO: 4. Redirect to Logto
(client_id, redirect_uri) LOGTO-->>USER: 5. Login Form USER->>LOGTO: 6. Enter Credentials
(Email, Password) LOGTO->>DB: 7. Validate Credentials DB-->>LOGTO: ✓ User Valid LOGTO->>LOGTO: 8. Generate JWT Token
(HS256, 1 hour expiry) LOGTO-->>USER: 9. Redirect to HRIS
with Authorization Code USER->>PAGES: 10. Request with Code PAGES->>API: 11. Exchange Code for Token
(server-side) API->>LOGTO: 12. Token Exchange LOGTO-->>API: 13. Return JWT API->>DB: 14. Verify User Role
& Permissions DB-->>API: 15. Return Role Data API-->>PAGES: 16. Set Secure Cookie
(httpOnly, secure, sameSite) PAGES-->>USER: 17. Redirect to Dashboard USER->>PAGES: 18. Load Dashboard PAGES->>API: 19. API Call with JWT API->>API: 20. Validate JWT Signature API-->>PAGES: 21. ✓ Authorized Response PAGES-->>USER: 22. Render Dashboard

graph TD ATT["📍 Attendance Data
Check-in/out Records"] LEA["📅 Leave Data
Approved Leave Days"] BEN["💳 Benefits Data
Enrollments, Deductions"] TAX["💼 Tax Configuration
Tax Rates, Rules"] OVERTIME["⏰ Overtime Data
Extra Hours"] CALC["🖥️ Payroll Calculation
Engine"] ATT --> CALC LEA --> CALC BEN --> CALC TAX --> CALC OVERTIME --> CALC CALC --> SALARY["💰 Salary Components
Base, Allowances"] CALC --> DEDUCT["📝 Deductions
Taxes, Benefits"] CALC --> NET["💵 Net Salary
Amount"] SALARY --> SLIP["📄 Payslip
Generation"] DEDUCT --> SLIP NET --> SLIP SLIP --> NOTIF["🔔 Notification
Send to Employee"] SLIP --> BANK["🏦 Bank Transfer
Payment Processing"] SLIP --> ARCHIVE["🗄️ Archival
Compliance Storage"] NOTIF -.->|LINE, Email| EMP["Employee"] BANK -.->|Transfer| BANKSVR["Bank Server"] ARCHIVE -.->|Store| STORAGE["Storage"] style CALC fill:#8b5cf6,color:#fff style SLIP fill:#3b82f6,color:#fff style ATT fill:#f59e0b,color:#fff style LEA fill:#f59e0b,color:#fff style BEN fill:#f59e0b,color:#fff

erDiagram EMPLOYEE ||--o{ DEPARTMENT : "belongs_to" EMPLOYEE ||--o{ POSITION : "has" EMPLOYEE ||--o{ EMPLOYEE : "reports_to" EMPLOYEE ||--o{ ATTENDANCE_RECORD : "has" EMPLOYEE ||--o{ LEAVE_REQUEST : "creates" EMPLOYEE ||--o{ LEAVE_BALANCE : "has" EMPLOYEE ||--o{ PAYSLIP : "receives" EMPLOYEE ||--o{ BENEFIT_ENROLLMENT : "enrolls" EMPLOYEE ||--o{ APPRAISAL : "has" EMPLOYEE ||--o{ PERFORMANCE_GOAL : "has" LEAVE_REQUEST ||--o{ LEAVE_APPROVAL : "requires" LEAVE_BALANCE ||--o{ LEAVE_REQUEST : "tracks" PAYSLIP ||--o{ SALARY_COMPONENT : "includes" PAYSLIP ||--o{ DEDUCTION : "deducts" BENEFIT ||--o{ BENEFIT_ENROLLMENT : "enrolls" BENEFIT ||--o{ BENEFIT_COST : "has" DEPARTMENT ||--o{ TEAM : "contains" TEAM ||--o{ EMPLOYEE : "has_members" APPRAISAL ||--o{ APPRAISAL_RESULT : "produces" APPRAISAL ||--o{ APPRAISAL_COMMENT : "has"

graph TB subgraph CurrentArch["🏗️ Current: Monolith
In-Memory EventBus"] direction TB subgraph Modules["📦 Business Modules"] AUTHM["auth module"] ORGM["org module"] EMPM["employee module"] ATTM["attendance module"] LEAM["leave module"] PAYM["payroll module"] end subgraph EventBus["🚌 In-Memory Event Bus"] PUBLISHER["Event Publisher
register_listener()
publish_event()"] DISPATCHER["Event Dispatcher
Direct Function Calls"] LISTENERS["Event Listeners
Synchronous"] end end subgraph FutureArch["🔮 Future: Microservices
Redis PubSub"] direction TB subgraph MS_Modules["📦 Microservices"] MS_AUTH["auth-service"] MS_ORG["org-service"] MS_EMP["employee-service"] MS_ATT["attendance-service"] MS_LEA["leave-service"] MS_PAY["payroll-service"] end subgraph MessageBroker["🚌 Redis PubSub"] REDIS_PUB["Publisher
PUBLISH channel"] REDIS_BROKER["Message Broker
Async Queue"] REDIS_SUB["Subscribers
SUBSCRIBE"] end subgraph DeadLetter["💀 Dead Letter Queue"] DLQ["Failed Events
Retry 3x
Exponential backoff"] end end %% Current Architecture AUTHM -->|publishes| PUBLISHER ORGM -->|publishes| PUBLISHER EMPM -->|publishes| PUBLISHER ATTM -->|publishes| PUBLISHER LEAM -->|publishes| PUBLISHER PAYM -->|publishes| PUBLISHER PUBLISHER -->|dispatch| DISPATCHER DISPATCHER -->|direct call| LISTENERS LISTENERS -->|listen| AUTHM LISTENERS -->|listen| ORGM LISTENERS -->|listen| EMPM LISTENERS -->|listen| ATTM LISTENERS -->|listen| LEAM LISTENERS -->|listen| PAYM %% Future Architecture MS_AUTH -->|publishes| REDIS_PUB MS_ORG -->|publishes| REDIS_PUB MS_EMP -->|publishes| REDIS_PUB MS_ATT -->|publishes| REDIS_PUB MS_LEA -->|publishes| REDIS_PUB MS_PAY -->|publishes| REDIS_PUB REDIS_PUB -->|async| REDIS_BROKER REDIS_BROKER -->|distribute| REDIS_SUB REDIS_SUB -->|subscribe| MS_AUTH REDIS_SUB -->|subscribe| MS_ORG REDIS_SUB -->|subscribe| MS_EMP REDIS_SUB -->|subscribe| MS_ATT REDIS_SUB -->|subscribe| MS_LEA REDIS_SUB -->|subscribe| MS_PAY REDIS_BROKER -->|failed| DLQ DLQ -->|retry| REDIS_BROKER style CurrentArch fill:#dbeafe,stroke:#0284c7,stroke-width:2px style FutureArch fill:#fed7aa,stroke:#ea580c,stroke-width:2px