Composable Commerce

Composable commerce is the practical application of the MACH (Microservices, API-first, Cloud-native, Headless) architecture pattern to ecommerce. Instead of buying one platform that does everything, the merchant assembles a stack from specialist services: a checkout layer (Shopify Plus or commercetools), a CMS for content (Contentful or Sanity), a search engine (Algolia or Elastic), a promotions engine (Talon.One or Voucherify), a payments layer (Stripe or Adyen), an OMS for orchestration, and so on. Each service exposes APIs and the storefront orchestrates them. The architecture pattern emerged because monolithic platforms were forcing tradeoffs: SAP Commerce Cloud has world-class B2B orchestration but mediocre storefront flexibility; Shopify has world-class storefront and checkout but limited custom-payment-flow control; Salesforce Commerce Cloud has strong personalization but heavy implementation cost. Composable lets the merchant pick the best in each layer without compromising elsewhere. The trade-offs that matter for margin: (1) per-service integration cost — every new service adds a contract and a maintenance burden; (2) data unification challenge — order, customer, and product data lives across multiple systems and must be reconciled for reporting; (3) checkout-time latency — every additional service adds latency to the cart-to-confirm path; (4) margin enforcement complexity — when discount logic lives in a promo engine, freight logic in a 3PL, COGS in an ERP, and FX in treasury, the margin layer must orchestrate all four in real time. For a profit firewall like Agentis, composable architecture is the natural deployment shape: Agentis sits between the cart and order-confirm, pulls live cost data from the ERP/MDM/treasury, evaluates the post-discount cart against margin policy, and returns approve/modify/reject in under 10ms. The composable pattern is what makes that possible without rewriting the underlying commerce platform. Composable commerce is now the dominant pattern at the enterprise tier ($50M+ GMV) and is increasingly common at upper-mid-market ($10-50M).