E-Commerce Platform Architecture & Integration Specification

1. Project Context
Rebuilding the digital commerce architecture for a premier Italian luxury retailer headquartered in Florence. The objective is to design, configure, and integrate a high-converting, headless Shopify Plus / Custom E-Commerce architecture to replace legacy store modules, backed by full Figma UI/UX design assets.

2. Technical Stack & Platform Architecture
Core Engine: Shopify Plus / Headless Commerce Framework.Storefront Integration: Next.js / Storefront API / GraphQL.Database & Caching: Redis session caching, PostgreSQL for custom middleware services.Payment & Localization: Stripe Connect, Klarna, PayPal Commerce, Shopify Markets (multi-currency: EUR, USD, GBP, JPY, AED).Integrations: ERP inventory sync (SAP/Custom REST endpoints), Klaviyo CRM, Algolia Search Engine.

3. Core Development Scope
Headless Storefront & API Integration: Establish optimized GraphQL schemas connecting the Next.js storefront to Shopify Storefront API for high-frequency inventory, cart, and collection queries.Custom Cart Engine & Checkout Funnel: Implement server-side multi-currency cart state, regional tax calculation rules, promotional coupon engine, and dynamic shipping threshold logic.Multi-Facet Catalog & Search Engine: Integrate Algolia / custom GraphQL filtering algorithms for sub-100ms multi-attribute queries (brand, size, material, season, color, price range).Automated Middleware & ERP Synchronization: Build Node.js webhooks to synchronize real-time warehouse inventory, order statuses, and customer records with the enterprise ERP system.Localized Checkout & Payment Gateways: Configure multi-currency payment routing, localized tax handling, guest checkout mechanics, and post-purchase webhook pipelines.

4. Performance & SLA Benchmarks
API Latency: Storefront API response time $< 150\text{ms}$ globally.Throughput & Concurrency: Scaled architecture capable of handling flash-sale spikes ($> 2,500$ concurrent active checkout sessions).Reliability: $99.95\%$ Uptime SLA with automated automated failovers and transaction recovery logs.

5. Delivery Schedule & Financial Milestones
Total Project Budget: $4,800 USD (Fixed-Price)Execution Timeframe: 5 WeeksWeeks 1–2: Architecture Setup, API Layer & Catalog Engine ($1,600)
├── Platform environment setup, GraphQL schema optimization, and middleware configuration
└── Enterprise product catalog ingestion, taxonomy mapping, and Algolia search integration

Weeks 3–4: Cart State, Multi-Currency Checkout & Middleware Integration ($1,800)
├── Server-side cart engine, dynamic tax calculation, and multi-currency payment routing
└── ERP inventory webhook synchronization pipelines and transactional email integration

Week 5: QA, Security Audit, Load Testing & Deployment ($1,400)
├── Load testing under high concurrency, vulnerability mitigation, and payment gateway certification
└── Production launch, DNS propagation, and live staging handoff


6. Candidate Qualification Requirements
Extensive experience engineering enterprise-grade e-commerce solutions (Shopify Plus Headless, Commercetools, or custom Node.js setups).Mastery of GraphQL APIs, REST middleware development, serverless functions, and relational/NoSQL databases.Proven track record of integrating complex ERPs, CRMs, and international payment architectures.Ability to start immediately and maintain structured Git workflows throughout the 5-week sprint.