E-commerce architect specializing in designing complete e-commerce platforms: headless commerce (Shopify Hydrogen, Medusa, Saleor, commercetools, Vendure), marketplace multi-vendor, B2B commerce, subscription commerce, MACH/composable architecture, omnichannel retail, product management, order processing, payment flows, inventory, and scalability for high-traffic events (Black Friday, flash sales). Use when designing e-commerce system architecture.

E-commerce payments advisor specializing in payment gateway integration (Stripe, PayPal, Adyen, Square, Braintree, Mollie, Razorpay, Checkout.com), PCI compliance, subscription billing, multi-currency handling, fraud prevention, BNPL (Klarna, Affirm, Afterpay), Apple/Google Pay, crypto payments (BitPay, BTCPay), payment orchestration (Primer, Spreedly), and 3DS2. Use when implementing or reviewing payment flows.

E-commerce architect specializing in designing complete e-commerce platforms: headless commerce (Shopify Hydrogen, Medusa, Saleor, commercetools, Vendure), marketplace multi-vendor, B2B commerce, subscription commerce, MACH/composable architecture, omnichannel retail, product management, order processing, payment flows, inventory, and scalability for high-traffic events (Black Friday, flash sales). Use when designing e-commerce system architecture.

E-commerce payments advisor specializing in payment gateway integration (Stripe, PayPal, Adyen, Square, Braintree, Mollie, Razorpay, Checkout.com), PCI compliance, subscription billing, multi-currency handling, fraud prevention, BNPL (Klarna, Affirm, Afterpay), Apple/Google Pay, crypto payments (BitPay, BTCPay), payment orchestration (Primer, Spreedly), and 3DS2. Use when implementing or reviewing payment flows.

Shopping cart and checkout flow design: cart architectures (session, DB, Redis, headless cart APIs), express checkout (Apple Pay, Google Pay, Shop Pay, Amazon Pay), shipping integration (ShipStation, Shippo, EasyPost), tax engines (Avalara, TaxJar), promotion/discount engine, cart recovery (Klaviyo, Omnisend), BOPIS (buy online pick up in-store), guest checkout, address validation, and checkout conversion optimization.

E-commerce analytics: conversion funnel tracking (browse to purchase), revenue attribution, cohort analysis, customer lifetime value (CLV), RFM segmentation, A/B test analysis (statistical significance), and key metrics (AOV, conversion rate, cart abandonment rate, repeat purchase rate).

Inventory management for e-commerce: WMS integration (warehouse management systems), dropshipping, 3PL (ShipBob, Flexport), demand forecasting, lot/batch tracking, inventory valuation (FIFO/LIFO/ weighted average), cycle counting, stock tracking (available, reserved, committed), multi-location inventory, backorder handling, reservation patterns, stock alerts, and inventory sync across channels.

Order processing for e-commerce: order state machine (pending through delivered/cancelled/returned), fulfillment workflows, returns/exchanges (RMA), invoice/receipt generation, order event sourcing, split shipments, and order notifications.

Payment gateway integration patterns for e-commerce: Stripe, PayPal, Adyen, Square, Mollie, Razorpay, Checkout.com, BNPL (Klarna, Affirm, Afterpay), crypto payments (BitPay, BTCPay), payment orchestration (Primer, Spreedly), 3DS2 authentication, fraud prevention (Sift, Riskified), subscription billing, refunds/disputes, multi-currency, and idempotency.

PCI DSS compliance for e-commerce: compliance levels (SAQ A, SAQ A-EP, SAQ D), cardholder data handling, tokenization (Stripe, Braintree tokens), secure payment forms (iframes, hosted fields), network segmentation, vulnerability scanning, penetration testing, and compliance audit preparation.

Product catalog design for e-commerce: headless platforms (Shopify, Medusa, Saleor, commercetools, Vendure), PIM integration (Akeneo, Pimcore, Salsify), data modeling (products, variants, attributes, categories, collections), GS1/GTIN barcodes, configurable/bundled products, dynamic pricing, reviews and ratings (Bazaarvoice, Yotpo), feed syndication (Google Shopping, Facebook Catalog), schema.org Product markup, tax calculation (Avalara, TaxJar), multi-language/localization, catalog search indexing, and image/media management.

Search and merchandising for e-commerce: product search relevance tuning, faceted navigation, recommendation engine patterns (collaborative filtering, content-based), A/B testing for layouts, personalization, and SEO for product pages.