Headless Commerce Shootout: Medusa vs. Saleor vs. Vendure (2026 Edition)

1. Architectural Runtimes & Engine Philosophy

Understanding the internal engine structure is critical before writing a single line of client code. E-commerce cores fail not at initial setup, but eighteen months in when your catalog reaches 200,000 SKUs and fulfillment requires bi-directional ERP syncing.

2. Extensibility Models: Extending the Core Without Breaking Upgrades

How does each framework handle a common business requirement: "Calculate a dynamic B2B volume discount based on corporate credit limits stored in an external CRM"?

import { createStep, createWorkflow, StepResponse } from "@medusajs/framework/workflows-sdk";

export const applyB2bDiscountStep = createStep(
  "apply-b2b-discount",
  async ({ cartId, companyTier }: { cartId: string; companyTier: string }, { container }) => {
    const cartService = container.resolve("cart");
    const discountMultiplier = companyTier === "ENTERPRISE" ? 0.85 : 0.95;
    
    const previousState = await cartService.getCartSnapshot(cartId);
    await cartService.applyCustomMultiplier(cartId, discountMultiplier);
    
    return new StepResponse({ applied: true, discountMultiplier }, previousState);
  },
  async (previousState, { container }) => {
    // Compensation logic if downstream payment fails
    const cartService = container.resolve("cart");
    await cartService.restoreSnapshot(previousState);
  }
);

import { OrderCalculationStrategy, RequestContext, Order } from '@vendure/core';

export class B2BVolumePricingStrategy implements OrderCalculationStrategy {
  async calculatePrice(ctx: RequestContext, order: Order) {
    const customerGroup = ctx.activeUserId ? await this.getGroup(ctx) : null;
    if (customerGroup?.name === 'Enterprise') {
      return order.subTotal * 0.85; // 15% contractual volume discount
    }
    return order.subTotal;
  }
}

3. Throughput & Concurrency Benchmarks (500 req/s Sustained Load)

We executed a 15-minute k6 load trial testing catalog searches, cart mutations, and checkout initializations across identical server specifications: 4 vCPU, 8 GB RAM, NVMe storage, PostgreSQL 16 on Ubuntu 24.04.

Key Finding: Vendure and Medusa v2 both demonstrate exceptional performance in Node/TypeScript runtimes with low baseline memory usage. Saleor’s Python/Django worker pool requires more memory overhead to handle high concurrent HTTP connections, making Redis-backed Celery worker tuning mandatory at scale.

4. Self-Hosting Total Cost of Ownership (TCO) vs. Shopify Plus

The financial rationale for open-source headless commerce becomes undeniable once a brand processes more than $10M in annual GMV:

5. The Decision Framework: Which Platform Should You Choose?