Money+ Congo

graph TB subgraph CHANNELS["Access Channels"] APP["Mobile App
(Flutter - iOS & Android)"] USSD["USSD Gateway
Dedicated Short Code
Offline Access"] WHATSAPP["WhatsApp Bot
Payment & Transfers"] QR["QR Code Payments
Scan-to-Pay"] WEB["Admin Dashboard
(React Web)"] MERCHANT["Merchant Portal
(Future)"] end subgraph GATEWAY["API Gateway & Load Balancer"] LB["Nginx / AWS ALB
SSL Termination
Rate Limiting"] WAF["Web Application Firewall
DDoS Protection"] end subgraph CORE["Core Backend (Go / Gin)"] AUTH["Auth Service
JWT + OTP + PIN + 2FA"] TXN["Transaction Engine
Atomic Operations
Mutex Locking"] WALLET["Wallet Service
Multi-currency
Fiat + Crypto"] AGENT_SVC["Agent Service
Float Management
Commission Engine"] CARD_SVC["Card Issuance
Virtual + Physical"] IBAN_SVC["IBAN Service
International Transfers
SWIFT/SEPA"] LOAN_SVC["Lending Engine
Credit Scoring
Loan Management"] NOTIF_SVC["Notification Service
Push + SMS + Email"] KYC_SVC["KYC/AML Engine
Identity Verification"] ANALYTICS_SVC["Analytics Engine
Real-time Reporting"] end subgraph DATA["Data Layer"] MYSQL[(MySQL Primary
100 conn pool)] REDIS[(Redis Cache
Sessions + OTP + Rates)] S3["Object Storage
KYC Docs + Avatars"] end subgraph EXTERNAL["External Service Providers"] direction LR MM["Mobile Money
M-Pesa, Airtel, Orange"] BANK["Banking Rails
SWIFT, SEPA, Local Banks"] CRYPTO_EX["Crypto Exchanges
Binance, Coinbase"] CARD_NET["Card Networks
Visa, Mastercard"] SMS_GW["SMS Gateway
Africa's Talking"] EMAIL_SVC["Email Service
SendGrid"] KYC_PRV["KYC Provider
Smile Identity"] IBAN_PRV["IBAN Provider
Banking Circle / CurrencyCloud"] WA_API["WhatsApp Business API
Meta Cloud API"] USSD_GW["USSD Aggregator
Africa's Talking"] end APP -->|HTTPS + JWT| LB USSD -->|USSD Protocol| USSD_GW USSD_GW -->|HTTPS| LB WHATSAPP -->|Webhook| WA_API WA_API -->|HTTPS| LB QR -->|Deep Link| APP WEB -->|HTTPS + Admin JWT| LB LB --> WAF --> CORE CORE --> DATA TXN --> MM TXN --> BANK IBAN_SVC --> IBAN_PRV IBAN_SVC --> BANK CARD_SVC --> CARD_NET WALLET --> CRYPTO_EX NOTIF_SVC --> SMS_GW NOTIF_SVC --> EMAIL_SVC KYC_SVC --> KYC_PRV LOAN_SVC --> ANALYTICS_SVC AUTH --> REDIS style CHANNELS fill:#e3f2fd,stroke:#1565c0,stroke-width:2px style GATEWAY fill:#fce4ec,stroke:#c62828,stroke-width:2px style CORE fill:#e8f5e9,stroke:#2e7d32,stroke-width:2px style DATA fill:#f3e5f5,stroke:#7b1fa2,stroke-width:2px style EXTERNAL fill:#fff3e0,stroke:#e65100,stroke-width:2px

graph LR subgraph MOBILE["Mobile App (Primary)"] FLUTTER["Flutter App
iOS + Android
40+ screens
Full feature set"] end subgraph USSD_CH["USSD Channel"] USSD_FLOW["Dedicated Short Code
Works on any phone
No internet required
Menu-based navigation"] end subgraph WA_CH["WhatsApp Bot"] WA_FLOW["WhatsApp Business API
Send/Receive money
Check balance
Pay bills via chat"] end subgraph QR_CH["QR Code Payments"] QR_FLOW["Dynamic QR Generation
Merchant scan-to-pay
P2P payments
Amount pre-filled"] end subgraph WEB_CH["Web Admin"] WEB_FLOW["React Dashboard
User management
Agent monitoring
KYC review"] end subgraph API_CH["Developer API"] API_FLOW["RESTful API
Merchant integration
Payment gateway
Webhooks"] end subgraph AGENT_CH["Agent Network"] AGENT_FLOW["Agent App (Flutter)
Cash-in / Cash-out
Float management
Commission tracking"] end FLUTTER --> CORE((Core API)) USSD_FLOW --> CORE WA_FLOW --> CORE QR_FLOW --> FLUTTER WEB_FLOW --> CORE API_FLOW --> CORE AGENT_FLOW --> CORE style MOBILE fill:#e3f2fd,stroke:#1565c0,stroke-width:2px style USSD_CH fill:#e8f5e9,stroke:#2e7d32,stroke-width:2px style WA_CH fill:#e8f5e9,stroke:#2e7d32,stroke-width:2px style QR_CH fill:#fff3e0,stroke:#e65100,stroke-width:2px style WEB_CH fill:#f3e5f5,stroke:#7b1fa2,stroke-width:2px style API_CH fill:#fce4ec,stroke:#c62828,stroke-width:2px style AGENT_CH fill:#fff3e0,stroke:#e65100,stroke-width:2px

flowchart LR PHONE["Any Phone
(No internet needed)"] -->|"Dial USSD Code"| TELCO["Telco Network
(Vodacom/Airtel/Orange)"] TELCO -->|"USSD Session"| AGG["USSD Aggregator
(Africa's Talking)"] AGG -->|"HTTP Callback"| API["Money+ API Server"] API -->|"Menu Response"| AGG AGG -->|"USSD Response"| PHONE subgraph USSD_MENUS["USSD Menu Tree"] M1["1. Send Money"] M2["2. Check Balance"] M3["3. Buy Airtime"] M4["4. Pay Bills"] M5["5. Withdraw"] M6["6. Mini Statement"] M7["7. Request Loan"] end

flowchart LR USER["User on WhatsApp"] -->|"Message"| META["Meta WhatsApp
Business API"] META -->|"Webhook POST"| BOT["Money+ Bot Server
(Go microservice)"] BOT -->|"Process Command"| CORE["Core Transaction API"] CORE -->|"Result"| BOT BOT -->|"Reply Message"| META META -->|"Deliver"| USER subgraph COMMANDS["Bot Commands"] C1["'send 5000 to +243...' → Transfer"] C2["'balance' → Check Balance"] C3["'topup 2000' → Buy Airtime"] C4["'pay SNEL 12345' → Bill Payment"] C5["'loan 50000' → Loan Application"] C6["'statement' → Mini Statement"] end

flowchart LR MERCHANT["Merchant displays
QR Code"] -->|"Customer scans"| APP["Money+ App
Camera/Scanner"] APP -->|"Decode QR payload"| PARSE["Parse: merchant_id
amount, currency, ref"] PARSE -->|"Show confirmation"| CONFIRM["Confirm Payment
Enter PIN"] CONFIRM -->|"POST /api/v1/send"| API["Core API
Process Payment"] API -->|"Notification"| MERCHANT API -->|"Receipt"| APP subgraph QR_TYPES["QR Code Types"] STATIC["Static QR
Fixed merchant ID
Customer enters amount"] DYNAMIC["Dynamic QR
Pre-filled amount
One-time use"] P2P_QR["P2P QR
User-to-user
Share payment link"] end

erDiagram User ||--o{ Wallet : has User ||--o{ Transaction : sends User ||--o{ Transaction : receives User ||--o{ Card : owns User ||--o{ Contact : saves User ||--o{ Notification : receives User ||--|| TransactionPIN : secures User ||--|| KYCSubmission : verifies User ||--|| SecuritySettings : configures User ||--|| NotificationSettings : configures User ||--|| UserPreferences : sets User ||--|| Budget : defines User ||--o{ UserSession : logs User ||--o{ CryptoHolding : holds User ||--o{ ChatMessage : chats User ||--o{ PaymentRequest : creates User ||--o| AgentFloat : manages User ||--o{ AgentCommission : earns User ||--o| IBAN : assigned User ||--o{ Loan : applies SplitPayment ||--o{ SplitMember : includes AdminUser ||--o{ AuditLog : creates User { uint id PK string name string email UK string phone UK string password_hash string country string role "user | agent" bool kyc_verified string iban } Wallet { uint id PK uint user_id FK string currency "CDF | USD | EUR" float balance string type "fiat | crypto" } Transaction { uint id PK uint sender_id FK uint receiver_id FK float amount float fee string type "send | deposit | withdraw | cash_in | cash_out" string status "pending | completed | failed" string reference UK } Loan { uint id PK uint user_id FK float amount float interest_rate int term_months float monthly_payment string status "pending | approved | active | repaid | defaulted" } IBAN { uint id PK uint user_id FK string iban_number UK string bic string currency string provider "banking_circle | currencycloud" }

flowchart TB subgraph L1["Layer 1: Network"] WAF["WAF - DDoS Protection"] SSL["TLS 1.3 Encryption"] RATE["Rate Limiting
100 req/min per IP"] end subgraph L2["Layer 2: Authentication"] JWT_AUTH["JWT Tokens
72-hour expiry"] OTP_2FA["OTP via SMS/Email
6-digit, 10-min expiry"] BIO["Biometric Auth
Face ID / Fingerprint"] end subgraph L3["Layer 3: Authorization"] ROLE["Role-Based Access
user | agent | admin"] PIN_V["Transaction PIN
4-digit, bcrypt hashed
Required before every txn"] GUARD["Route Guards
AgentOnly / AdminRequired"] end subgraph L4["Layer 4: Data"] BCRYPT["bcrypt Password Hashing
Cost factor: 10"] ENCRYPT["AES-256 Encryption
Sensitive fields at rest"] AUDIT["Full Audit Trail
Admin action logging"] end subgraph L5["Layer 5: Compliance"] KYC_AML["KYC/AML Verification
Smile Identity"] TXN_MON["Transaction Monitoring
Chainalysis"] SANCTIONS["Sanctions Screening
PEP / OFAC lists"] LIMITS["Transfer Limits
Daily: 5M CDF
Single: 1M CDF"] end L1 --> L2 --> L3 --> L4 --> L5 style L1 fill:#fce4ec,stroke:#c62828,stroke-width:1px style L2 fill:#fff3e0,stroke:#e65100,stroke-width:1px style L3 fill:#e3f2fd,stroke:#1565c0,stroke-width:1px style L4 fill:#e8f5e9,stroke:#2e7d32,stroke-width:1px style L5 fill:#f3e5f5,stroke:#7b1fa2,stroke-width:1px

graph TB subgraph DOMESTIC["Domestic Payments (DRC)"] MM_MPESA["Vodacom M-Pesa
STK Push / B2C / C2B"] MM_AIRTEL["Airtel Money
Collection & Disbursement"] MM_ORANGE["Orange Money
Payment API"] MM_AFRICELL["Africell Money"] LOCAL_BANK["Local Banks
Rawbank, TMB, Equity
Account-to-account"] AGENT_NET["Agent Network
10,000+ Cash Points
Cash-in / Cash-out"] end subgraph IBAN_SYS["IBAN & International Transfers"] IBAN_ISSUE["IBAN Issuance
Each user gets a unique IBAN
via Banking Circle / CurrencyCloud"] SEPA["SEPA Transfers
EUR zone, 0-2 days
Low cost"] SWIFT_NET["SWIFT Network
Global coverage
1-5 business days"] CORRESPONDENT["Correspondent Banks
USD nostro/vostro accounts"] end subgraph CARD_PAY["Card Payments"] VISA["Visa Network
Card issuance + processing"] MC["Mastercard Network
Card issuance + processing"] THREE_DS["3D Secure
Transaction verification"] end subgraph QR_PAY["QR Payments"] STATIC_QR["Static Merchant QR
Printed at POS"] DYNAMIC_QR["Dynamic QR
Generated per transaction"] NFC["NFC Tap-to-Pay
(Future)"] end USER((User)) --> DOMESTIC USER --> IBAN_SYS USER --> CARD_PAY USER --> QR_PAY IBAN_ISSUE -->|"Receive international
wire transfers"| SWIFT_NET IBAN_ISSUE -->|"Receive EUR
transfers"| SEPA SWIFT_NET --> CORRESPONDENT style DOMESTIC fill:#e8f5e9,stroke:#2e7d32,stroke-width:1px style IBAN_SYS fill:#e3f2fd,stroke:#1565c0,stroke-width:2px style CARD_PAY fill:#f3e5f5,stroke:#7b1fa2,stroke-width:1px style QR_PAY fill:#fff3e0,stroke:#e65100,stroke-width:1px

flowchart TD APPLY([User Applies for Loan]) --> ELIGIBLE{"Eligibility Check
- KYC verified?
- Account age > 30 days?
- Transaction history?
- No active defaults?"} ELIGIBLE -->|Fail| DENIED["Application Denied
Show reason + retry date"] ELIGIBLE -->|Pass| SCORE["Credit Scoring Engine"] subgraph SCORING["Credit Scoring Model"] S1["Transaction Frequency
Weight: 25%"] S2["Average Balance
Weight: 20%"] S3["Income Regularity
Weight: 20%"] S4["Repayment History
Weight: 25%"] S5["Account Age
Weight: 10%"] end SCORE --> SCORING SCORING --> CREDIT_SCORE["Credit Score: 0-1000"] CREDIT_SCORE --> OFFER["Generate Loan Offer
Amount: up to 3x avg monthly income
Interest: 5-15% per month
Term: 7-90 days"] OFFER --> ACCEPT{User Accepts?} ACCEPT -->|No| CANCEL[Application Cancelled] ACCEPT -->|Yes| DISBURSE["Instant Disbursement
Credit user's M+ Wallet"] DISBURSE --> REPAY_SCHED["Repayment Schedule
Auto-deduct from wallet
SMS reminders"] REPAY_SCHED --> REPAID{Fully Repaid?} REPAID -->|Yes| SCORE_UP["Improve Credit Score
Unlock higher limits"] REPAID -->|No, Overdue| COLLECT["Collection Process
SMS reminders → Restrict withdrawals
→ Report to credit bureau"] style SCORING fill:#f3e5f5,stroke:#7b1fa2,stroke-width:1px

flowchart TB subgraph CONCURRENT["Concurrent Requests"] R1["User A: Send 5000 CDF"] R2["User B: Withdraw 3000 CDF"] R3["Agent C: Cash-In 10000 CDF"] R4["User D: Buy BTC"] R5["USSD: Check Balance"] R6["WhatsApp: Pay Bill"] end R1 & R2 & R3 & R4 & R5 & R6 --> GIN["Gin HTTP Server
1 goroutine per request
Zero-allocation router"] GIN --> POOL["MySQL Connection Pool
Max Open: 100
Max Idle: 25
Lifetime: 5 min"] subgraph LOCKING["Balance Protection"] MUTEX["sync.Map per-wallet Mutex
Prevents double-spend"] DEADLOCK["Deadlock Prevention:
Always lock lower wallet ID first"] ATOMIC["Atomic SQL Updates:
SET balance = balance - ?
(not read-modify-write)"] GORM_TX["GORM Transaction:
Begin → Debit → Credit → Commit
Auto-rollback on failure"] end POOL --> LOCKING subgraph SCALE["Horizontal Scaling"] LB2["Load Balancer"] S1["Server 1"] S2["Server 2"] S3["Server N"] REDIS2["Redis (shared state)
Distributed locks
Session store"] end LB2 --> S1 & S2 & S3 S1 & S2 & S3 --> REDIS2 style CONCURRENT fill:#e3f2fd,stroke:#1565c0,stroke-width:1px style LOCKING fill:#fce4ec,stroke:#c62828,stroke-width:1px style SCALE fill:#e8f5e9,stroke:#2e7d32,stroke-width:1px

graph TB subgraph CI_CD["CI/CD Pipeline"] GIT["GitHub Repository"] --> GH_ACTIONS["GitHub Actions"] GH_ACTIONS --> TEST["Run Tests
Unit + Integration"] TEST --> BUILD["Build Docker Images"] BUILD --> PUSH["Push to Container Registry"] end subgraph PROD["Production (AWS / Azure)"] ALB["Application Load Balancer
+ WAF + SSL"] ECS1["Go API Server
(Container x3)"] ECS2["WhatsApp Bot
(Container x1)"] ECS3["USSD Handler
(Container x1)"] RDS["MySQL RDS
Multi-AZ Replica"] ELASTI["Redis ElastiCache
Cluster Mode"] S3_STORE["S3 Bucket
KYC Documents"] CLOUDFRONT["CloudFront CDN
Admin Dashboard"] end PUSH --> ALB ALB --> ECS1 & ECS2 & ECS3 ECS1 --> RDS ECS1 --> ELASTI ECS1 --> S3_STORE CLOUDFRONT --> WEB_APP["React Admin App"] subgraph MONITORING["Monitoring & Observability"] CW["CloudWatch Metrics"] SENTRY["Sentry Error Tracking"] GRAFANA["Grafana Dashboards"] PAGER["PagerDuty Alerts"] end ECS1 --> CW & SENTRY CW --> GRAFANA --> PAGER style CI_CD fill:#e3f2fd,stroke:#1565c0,stroke-width:1px style PROD fill:#e8f5e9,stroke:#2e7d32,stroke-width:2px style MONITORING fill:#fff3e0,stroke:#e65100,stroke-width:1px