​

Architecture

​

System Overview

​

Component Details

​

API Gateway

​

Recommendation Engine

• Language: TypeScript (Node.js)
• ML Model: Custom scoring algorithm
• Cache: Redis for hot data

​

Booking Service

​

Inventory Hub

1. Direct venue partnerships (highest margin)
2. Klook (good coverage, fast API)
3. Viator (extensive catalog)
4. GetYourGuide / KKday (backup)

​

Ground Truth Engine

-- Ground Truth Schema
CREATE TABLE ground_truth (
    id UUID PRIMARY KEY,
    booking_id UUID REFERENCES bookings(id),
    context_log_id UUID REFERENCES context_logs(id),
    activity_id UUID REFERENCES activities(id),
    verified_at TIMESTAMP NOT NULL,
    verification_method VARCHAR(20),
    user_profile JSONB,
    created_at TIMESTAMP DEFAULT NOW()
);

-- Index for efficient lookups
CREATE INDEX idx_gt_profile ON ground_truth
    USING GIN (user_profile);

​

Data Flow

​

Recommendation Flow

​

Booking Flow

​

Database Schema

​

Core Tables

​

Caching Strategy

​

Cache Layers

​

Cache Keys

# Context cache
context:{city}:{weather_hash} → enriched context

# Ground Truth aggregates
gt:{travel_type}:{city}:{category} → activity scores

# Inventory
inventory:{activity_id}:{date} → availability

​

Scalability

​

Horizontal Scaling

​

Performance Targets

​

Security

​

API Security

• Authentication: API key in x-api-key header
• Rate Limiting: Per-key limits
• IP Allowlisting: Optional for enterprise
• Encryption: TLS 1.3 for all connections

​

Data Security

• At Rest: AES-256 encryption
• In Transit: TLS 1.3
• PII Handling: Anonymization for ML
• Retention: Configurable per client

​

Monitoring

​

Key Metrics

​

Alerting

​

Next Steps