ChatGPT answers, unedited

For a freelance developer building custom client stores, I'd shortlist Vendure and Medusa. If your main criterion is “I need to integrate weird third-party systems without fighting the platform,” I'd currently give Vendure a slight edge.

My ranking for extensibility

🥇 Vendure — my pick for your use case

Vendure's plugin architecture is exceptionally well suited to agency/freelance work. A plugin can add database entities, services, REST endpoints, GraphQL queries/mutations, custom fields, event handlers, background jobs, and integrations with external systems. It's built on NestJS, so if you're comfortable with TypeScript, the mental model is very natural. docs.vendure.io

For example, a client says:

"When an order is placed, send it to our ERP, reserve inventory in another system, add a custom approval step, and expose the resulting status in the storefront."

That's basically what Vendure's plugin model is designed for.

You can keep the integration isolated:

plugins/
  erp/
  shipping/
  loyalty/
  marketplace/
  custom-pricing/

That is particularly attractive when you're building multiple stores for different clients because you can turn your integrations into reusable packages.

Vendure also has a plugin directory, so you aren't necessarily implementing every common integration yourself. docs.vendure.io

🥈 Medusa — arguably better for maximum architectural freedom

I'd choose Medusa if you want the commerce backend to behave more like a composable application framework.

Its architecture separates API routes → workflows → modules → data, and custom modules can integrate external services. Workflows are specifically designed to orchestrate operations across systems, including things such as ERP synchronization. docs.medusajs.com

That's excellent for projects like:

Storefront
   ↓
Medusa
   ├── Shopify-like commerce logic
   ├── ERP module
   ├── PIM module
   ├── CRM module
   ├── custom pricing
   └── fulfillment integration

The big advantage is that integrations become modules, rather than a pile of platform-specific hooks.

Medusa's own documentation describes it as a commerce framework intended to be customized around the business rather than merely configured. docs.medusajs.com

When I'd pick each

Choose Vendure if:

• You're primarily a TypeScript developer.
• You like NestJS/DI/modules.
• You want a very straightforward plugin architecture.
• Clients frequently need custom admin functionality.
• You want reusable integrations across projects.
• You want GraphQL but don't want to build everything yourself.

Choose Medusa if:

• You want maximum architectural control.
• Integrations/workflows are the heart of the project.
• You prefer a modular backend architecture.
• You're building unusual commerce experiences rather than conventional stores.
• You want to treat commerce as infrastructure inside a larger application.

Choose Sylius if:

• You're a strong PHP/Symfony developer.
• The client has complicated domain/business rules.
• You don't mind a more traditional framework-style development experience.

Choose Saleor if:

• GraphQL is central to your architecture.
• You're comfortable with Python/Django.
• The client needs sophisticated multi-channel/multi-warehouse commerce.

The important distinction

For a freelancer, I'd optimize less for “which has the most features?” and more for:

“Can I turn a client's bizarre requirement into an isolated module/plugin without modifying the core?”

That's where Vendure and Medusa stand out.

If I were starting an agency today and wanted one default platform for custom integration-heavy stores, I'd probably standardize on Vendure. If I wanted to build more application-like, highly bespoke commerce systems, I'd lean Medusa.

And I would not default to WooCommerce/Magento just because their ecosystems are larger—their ecosystems are fantastic, but custom integrations can increasingly become plugin/theme/core-hook archaeology rather than clean application development.

If you tell me your typical client stack (Next.js/React, PHP, Python, etc.) and the kinds of integrations you usually build (ERP, PIM, shipping, subscriptions, marketplaces, custom pricing), I can narrow this down to one.

If your main business is building custom integrations for clients, I’d shortlist Sylius, Shopware, and Medusa—and my default pick would be Sylius if you’re comfortable with PHP/Symfony.

My ranking for a freelance integration shop

🥇 Sylius — probably the best for your use case

Sylius is less of a "finished store builder" and more of an ecommerce framework built on Symfony. That distinction is valuable when you're repeatedly doing unusual integrations.

Its architecture is deliberately modular: you can replace individual pieces and connect external PIMs, CRMs, marketing systems, etc., rather than fighting a monolithic platform. It also exposes an API-first architecture through API Platform. plugins.sylius.com

The plugin ecosystem is also reasonably mature, with dedicated integrations for payments, shipping, ERP/CRM systems, search, marketing, and other services. addons.sylius.com

Why I'd choose it for a freelance business: you can treat each client integration as a proper Symfony module rather than accumulating hacks around an existing CMS.

🥈 Shopware — best if clients are more enterprise-oriented

Shopware is probably the strongest alternative.

Shopware has both Apps and Plugins. For self-hosted stores, plugins can deeply modify the application, while apps can keep logic outside the store and communicate through APIs/webhooks. developer.shopware.com

That gives you a particularly useful spectrum:

external integration → App → Plugin → deep platform customization

Shopware explicitly positions its APIs for ERP, PIM, CRM, custom frontends and other integrations. plugins.sylius.comwww.shopware.comossalt.com

I'd favor it over Sylius if your target clients are established retailers with complicated catalogs, ERP/PIM requirements, B2B workflows, multiple sales channels, etc.

🥉 Medusa — best if you're a TypeScript/Node developer

Medusa is attractive if you want to stay entirely in the JavaScript/TypeScript ecosystem. It's headless-first rather than a traditional PHP ecommerce application, which makes it particularly pleasant for custom React/Next.js storefronts and external services. Recent comparisons also put it among the leading developer-oriented open-source commerce backends. www.wpbundle.com

I'd pick Medusa over Sylius if your existing expertise is strongly TypeScript/Node and you're building mostly headless stores.

Where WooCommerce fits

WooCommerce is actually a very pragmatic freelance choice. Its enormous plugin ecosystem means you can solve a lot of ordinary requirements without writing them yourself. ossalt.com

But for unusual integrations and business logic, I prefer Sylius/Medusa. WooCommerce's WordPress/plugin architecture can become difficult to reason about when a project accumulates many third-party plugins and custom hooks.

What I'd do in your position

If you're trying to establish a repeatable freelance stack, I'd probably choose:

PHP/Symfony → Sylius
TypeScript/Node → Medusa
Enterprise/European merchants → Shopware

And I'd avoid Magento/Adobe Commerce unless your niche specifically demands it. It's extremely powerful, but "easy to extend" isn't the same thing as "powerful enough to extend."

The important distinction is that Sylius and Medusa let you make the commerce engine part of your application, whereas platforms like WooCommerce and Shopware start with a more complete merchant application and give you extension mechanisms around it.

If you tell me your preferred stack (PHP/TS/Python), typical client size, and whether you build headless storefronts, I can narrow this down to one platform and explain exactly how I'd structure your reusable integration architecture.

For a freelance developer building multiple client stores with bespoke integrations, I'd pick Medusa as the default.

My ranking

Why Medusa is particularly attractive for you

Medusa is essentially designed around the problem you're describing: take a commerce backend and adapt it to each client's business rather than forcing the business into the platform's model.

Its current architecture gives you:

• Custom modules for new domains/integrations, with their own data models and services.
• Workflows for complicated multi-step business operations, including rollback behavior.
• Custom API routes without having to build a separate integration service.
• Events/subscribers for synchronization and automation.
• Module replacement, so you can substitute parts of the commerce stack with your own implementation or a third-party service.
• Admin customization for client-specific back-office functionality.

Those aren't just theoretical extension points—the current documentation explicitly positions modules, workflows, API routes, data models, events, and admin customization as the normal way to customize a Medusa application. Medusa Docs Medusa Docs Medusa Docs

The architecture is especially nice for integrations. For example, you could have:

Medusa → custom ERP module → ERP

Medusa → custom fulfillment module → 3PL

Medusa → event subscriber → CRM

without turning the whole project into a pile of external middleware. Medusa's modules can encapsulate third-party integrations, and its workflows can orchestrate operations across them. Medusa Docs Medusa Docs

The big alternative: Sylius

If you're a PHP/Symfony developer, I'd seriously consider Sylius instead.

Sylius is arguably even more "framework-like" than Medusa. Its plugin architecture is excellent for turning client-specific functionality into reusable packages, and its ecosystem explicitly supports custom/internal plugins as well as community and commercial ones. Sylius Academy Sylius Addons Marketplace

So my rule of thumb would be:

TypeScript/Node → Medusa
PHP/Symfony → Sylius

Where WooCommerce fits

WooCommerce is the opposite tradeoff: its architecture isn't as elegant for deeply customized commerce systems, but its enormous plugin ecosystem can make ordinary client requirements dramatically faster.

If a client says:

"We need WordPress, Stripe, subscriptions, Mailchimp, a normal catalog, and a weird shipping plugin."

I'd probably choose WooCommerce.

If they say:

"We manufacture configurable products, have an ERP with unusual inventory semantics, need custom pricing rules, and orders have to flow through three external systems."

I'd much rather start with Medusa or Sylius.

What I'd build as a freelancer

I'd actually create a reusable Medusa starter rather than treating every client as a blank project:

your-commerce-starter/
├── modules/
│   ├── erp/
│   ├── shipping/
│   ├── customer-data/
│   └── ...
├── workflows/
│   ├── sync-order/
│   ├── sync-inventory/
│   └── ...
├── subscribers/
├── api/
├── admin/
└── storefront/

Then each client gets the starter plus their particular integrations. Medusa explicitly supports reusable modules/customizations, which makes this approach particularly attractive for an agency/freelancer workflow. Medusa Docs

Bottom line: if your differentiator is "I can connect your store to whatever weird systems your business uses," I'd choose Medusa first, Sylius second, and WooCommerce when its ecosystem saves you more work than its architecture costs you.

If you tell me your preferred stack (Node/TS, PHP, Python) and the kinds of integrations your clients usually need (ERP, POS, marketplaces, subscriptions, B2B pricing, etc.), I can narrow this down to a much more opinionated choice.

If your priority is “I need to build custom integrations for many different clients without fighting the platform,” my first choice today would be Medusa, with Vendure as a very close second.

My ranking for a freelance developer

1. 🥇 Medusa — probably what I'd pick for your business

Medusa documentation

Medusa is particularly attractive when your value as the developer is integrating the store with other systems.

Its architecture explicitly supports custom API routes, workflows, data models, modules, event subscriptions, admin customization, and integrations. docs.medusajs.comdocs.medusajs.com

For example, a client might need:

Shopify-like storefront + ERP + custom pricing engine + warehouse API + CRM + unusual checkout logic

Instead of building a separate integration service around the ecommerce platform, you can put much of that logic directly into Medusa's architecture. Its modules can also integrate external systems such as ERPs, fulfillment providers, CMSs, etc. docs.medusajs.comdocs.medusajs.com

It's also TypeScript/Node, which is a major advantage if you're already doing modern web development.

Why I like it for freelancing:

• TypeScript end-to-end
• Modular architecture
• Custom business logic is a first-class concept
• REST/API-oriented
• PostgreSQL
• Events and workflows
• Easy to build reusable integration modules
• Headless by design
• Self-hostable

The biggest downside is that you're choosing a relatively developer-centric commerce engine rather than an enormous traditional ecommerce ecosystem.

2. 🥈 Vendure — arguably even better if you love TypeScript + GraphQL

Vendure documentation

Vendure's plugin system is exceptionally good. Plugins can add database entities, modify configuration, extend GraphQL, communicate with external systems, react to events, and run background tasks. docs.vendure.io

That's almost exactly the feature set you'd want for client integrations.

For example, you could make:

client-project/
  plugins/
    erp-integration/
    custom-pricing/
    shipping-provider/
    loyalty/
    marketplace-sync/

And each piece can remain relatively isolated.

Vendure also lets you extend both its Shop API and Admin API with custom GraphQL queries/mutations. docs.vendure.io

I'd choose Vendure over Medusa when:

• You strongly prefer GraphQL
• You like NestJS/TypeScript architecture
• You expect complicated commerce rules
• You're doing B2B
• You want a very explicit plugin architecture

3. Shopware — excellent for bigger clients

Shopware developer documentation

Shopware is worth considering if your freelance clients are larger businesses, particularly in Europe.

Its self-hosted edition supports PHP plugins that can modify the database schema and use Symfony's extension mechanisms, alongside its app/API ecosystem. developer.shopware.com

It's more of a full-fledged established ecommerce platform than Medusa/Vendure.

That's both its strength and weakness:

Pros: mature commerce functionality, huge feature set, established ecosystem.

Cons: considerably more platform to learn and maintain.

For a freelancer doing lots of small-to-medium bespoke stores, I'd generally prefer Medusa/Vendure.

The interesting choice: Medusa vs Vendure

For your specific business, I'd narrow it down to these two.

Pick Medusa if:

“Every client has weird requirements, and I want the commerce engine to get out of my way.”

Pick Vendure if:

“I want a strongly structured ecommerce framework where custom functionality is packaged as clean TypeScript plugins.”

I'd personally lean Medusa for a freelance integration shop because its current framework is explicitly designed around customizations and integrations, including workflows and custom modules. docs.medusajs.comdocs.medusajs.com

One important distinction

If by "easiest to extend" you mean “I want to modify absolutely anything with the least resistance,” then WooCommerce deserves consideration. Its enormous WordPress/plugin ecosystem makes conventional customization incredibly accessible.

But if you mean:

“I want a clean technical foundation that I can repeatedly use to build bespoke commerce systems for clients.”

I'd choose Medusa → Vendure → Shopware, in that order.

If you tell me the kinds of integrations you typically build (ERP, shipping, POS, subscriptions, marketplaces, custom pricing, etc.), I can also compare Medusa vs Vendure specifically from a freelancer's perspective, including how I'd structure reusable plugins/modules across clients.

If custom integrations and developer extensibility are the priority, my first choice in 2026 is Medusa.

My ranking for a freelance developer

Why Medusa stands out: its architecture is explicitly designed around customization. You can create your own data models/modules, API routes, workflows, event subscribers, scheduled jobs, and admin extensions inside the application. Its modules can also encapsulate third-party integrations such as ERP, payment, fulfillment, CMS, etc. docs.medusajs.comdocs.medusajs.com

That maps extremely well to freelance work. For example, a client says:

"We need Shopify-like commerce, but orders have to sync to our ERP, pricing comes from our internal API, and checkout needs a custom approval workflow."

With Medusa, you can implement those as first-class modules/workflows rather than fighting a monolithic plugin system. You can also package your reusable customizations as plugins and reuse them across client projects. docs.medusajs.comdocs.medusajs.com

Medusa documentation

When I'd pick something else

Saleor would be my #2. It's exceptionally extensible through GraphQL, apps, webhooks, metadata, and API extensions. It's particularly attractive if you're already a Python/GraphQL shop or your clients need sophisticated multi-channel commerce. docs.saleor.io

Saleor documentation

Sylius is arguably better than Medusa if you're a strong PHP/Symfony developer and expect clients to need extremely deep customization of the commerce domain. Its flexibility comes with more framework-level complexity, though.

WooCommerce is the pragmatic choice when the client already lives in WordPress or needs access to an enormous existing ecosystem. But for new, integration-heavy, headless builds, I'd generally prefer Medusa's architecture over extending WordPress/WooCommerce.

For your specific business model

I'd lean toward Medusa + Next.js + PostgreSQL and build yourself a small reusable integration toolkit:

• ERP connector
• CRM/customer sync
• payment provider abstraction
• shipping/fulfillment connectors
• product/catalog importer
• webhook/event infrastructure
• client-specific modules
• reusable admin extensions

Medusa's module system is particularly useful here because custom modules can be reused across projects, and plugins can bundle modules, workflows, routes, subscribers, jobs, and admin extensions. docs.medusajs.comdocs.medusajs.com

So if your question is "Which platform will let me bend the ecommerce backend to whatever weird integration my next client asks for?" — Medusa is probably the easiest starting point.

If you tell me whether you prefer TypeScript, PHP, or Python, I can narrow it down to the best 2–3 choices for your stack and explain the tradeoffs.

If custom integrations and developer extensibility are your main criterion, I’d put Medusa at the top of the list.

My ranking for a freelance developer

🥇 Medusa — probably your best choice

Medusa is unusually well suited to the kind of work you're describing. Its framework lets you create custom data models, modules, API routes, workflows, event subscribers, scheduled jobs, and integrations inside the application, rather than having to bolt a separate service onto an otherwise rigid ecommerce platform. docs.medusajs.com

The particularly valuable feature for a freelancer is plugins. You can package a client-specific integration or reusable functionality as a plugin and install it across multiple Medusa projects. Plugins can contain modules, API routes, workflows, hooks, subscribers, jobs, links, and admin extensions. docs.medusajs.com

For example, you could eventually build your own reusable:

• ERP connector
• PIM connector
• custom B2B pricing system
• fulfillment integration
• subscription logic
• marketplace integration
• client-specific checkout functionality

…and reuse the underlying pieces across clients.

Medusa also explicitly supports using integrations as a middleware layer between commerce and external systems, including ERP, CMS, analytics, auth, storage, etc. docs.medusajs.com

Medusa Framework documentation

🥈 Saleor — excellent if you want everything API-first

Saleor is arguably the better choice if you want a strictly headless, API-centric architecture.

Saleor keeps its core relatively untouched and expects you to extend it through apps. Those apps communicate with Saleor through GraphQL and webhooks, and can have their own UI embedded into the dashboard. saleor.io

That's attractive for client work because you don't have to maintain a fork of the ecommerce core. Saleor also advertises 140+ webhook events and independently hosted apps/integrations. saleor.io

The tradeoff is architectural: Medusa feels more like a commerce framework you customize; Saleor feels more like a commerce engine you integrate with.

Saleor documentation

🥉 Sylius — fantastic if you're a Symfony/PHP developer

If you're already deeply comfortable with Symfony, I'd seriously consider Sylius. Its architecture is extremely customizable and is particularly good when the client's business rules are unusual.

But if you're starting from scratch and your goal is to build integrations quickly across many clients, I'd favor Medusa's TypeScript ecosystem.

What I'd choose for your business

If I were building a freelance ecommerce practice around custom integrations, I'd probably standardize on:

Medusa + Next.js + PostgreSQL + your own reusable integration plugins

That gives you a nice progression:

Client 1 → build integration
Client 2 → reuse 60–80% of it
Client 3 → turn it into a generic plugin
Client 10 → you've effectively built your own ecommerce integration toolkit

That's where Medusa is particularly compelling: its customization model is explicitly designed around reusable modules and plugins rather than repeatedly hacking the core. docs.medusajs.comdocs.medusajs.com

If you tell me what kinds of integrations your clients typically need (ERP, PIM, shipping, marketplaces, custom pricing, subscriptions, etc.), I can also compare Medusa vs Saleor vs Sylius specifically for that workload.

For your use case—freelance work where every client may need weird/custom integrations—I’d pick Medusa first, with Sylius as the main alternative.

My ranking for extensibility

Why I'd choose Medusa

Medusa is unusually well suited to the "client wants their ERP/CRM/warehouse/pricing system connected in some bizarre way" scenario.

Its architecture explicitly separates API routes → workflows → modules → database, and custom modules are first-class parts of the application. You can create your own data models and services and have them participate in the rest of the commerce system. docs.medusajs.comaddons.sylius.comdocs.saleor.io

More importantly for freelance work, integrations are treated as replaceable modules. Medusa documents custom providers for things like payments, fulfillment, notifications, storage, search, tax, authentication, and more. docs.medusajs.com

That means a client request like:

"When an order is placed, send it to our ERP, reserve inventory, create a shipping job, and update our CRM."

can be modeled as a proper workflow/integration rather than bolting a bunch of webhooks onto a monolithic store.

And plugins can package modules, API routes, workflows, subscribers, scheduled jobs, and admin extensions, which is particularly attractive if you're building reusable components across your freelance projects. docs.medusajs.com

Medusa documentation

Where Sylius beats it

If you're a strong PHP/Symfony developer, I'd seriously consider Sylius instead. Its plugin architecture is mature and designed specifically for modifying commerce behavior without changing core code. academy.sylius.com

The big advantage is that you're essentially working with a commerce-specific Symfony framework, so you get a very familiar, conventional PHP architecture rather than learning a platform-specific extension model.

Its plugin ecosystem is also substantial, covering integrations, payments, shipping, sales/conversion, analytics, accounting, etc. addons.sylius.com

Sylius

Saleor is a different flavor

Saleor is excellent if you want GraphQL + headless + external integrations.

Its model is deliberately API-first: webhooks, metadata, attributes, apps, API extensions, and dashboard extensions are the primary mechanisms for customization. docs.saleor.io

I'd choose Saleor when the client wants a highly decoupled architecture and you're comfortable treating the commerce backend more like an API platform.

I wouldn't choose it over Medusa for maximum freedom inside the backend, though. Medusa's ability to add your own modules and business logic directly into the application is a better match for "I need to make this client's commerce engine behave differently."

My practical recommendation

If you're a JS/TS freelancer, I'd standardize on:

Medusa + PostgreSQL + Next.js + your own reusable integration plugins

That gives you a nice progression:

• Normal store → mostly built-in Medusa functionality
• Custom fields/data → custom module
• External API → module/provider
• Complicated business process → workflow
• Event-driven sync → subscribers/events
• Reusable client functionality → plugin
• Custom admin functionality → admin extension

That's a very good abstraction for freelance projects because you can gradually increase customization without immediately forking the platform.

If you're PHP/Symfony-first, flip the recommendation to Sylius.

One caveat: "easiest to extend" isn't the same as "easiest to launch." WooCommerce can be faster for a conventional small store, while Medusa/Sylius start making more sense as soon as the client's requirements become integration-heavy or unusual.

For a freelance developer building custom integrations for multiple clients, I’d rank them differently than I would for a merchant choosing a store platform. You care about:

• how fast you can understand the codebase
• how safely you can add custom business logic
• how easy upgrades are after you hand it off
• how many client-specific integrations you can build without fighting the framework

My shortlist:

www.wpbundle.com

My default choice for a freelance integration shop: Medusa

If you’re comfortable with TypeScript, Medusa is probably the nicest platform to extend today. Its architecture is built around modules rather than modifying a giant monolith:

• custom payment providers
• ERP connectors
• fulfillment workflows
• subscription logic
• custom pricing rules
• marketplace features
• external inventory systems

You can keep your client-specific logic in modules instead of patching core code. That makes future upgrades much less painful. www.wpbundle.com

The tradeoff: if a client says "we need a weird local shipping carrier integration," WooCommerce might already have a plugin, while Medusa may mean you build it yourself. www.wpbundle.com

When I would pick WooCommerce instead

For many freelance projects, the fastest money is still:

WooCommerce + custom plugin + API integrations

Choose it when the client needs:

• WordPress content marketing
• lots of existing payment/shipping plugins
• nontechnical staff who already know WordPress
• a conventional online store

The ecosystem is enormous, which means fewer things you have to build yourself. The downside is that plugin quality varies and complex customizations can become a dependency-management problem. www.wpbundle.comwww.wpbundle.com

When I would pick Saleor

Pick Saleor for clients with more "application" requirements:

• multiple warehouses
• multiple channels
• complex permissions
• international commerce
• custom frontends

Its GraphQL-first approach makes integrations clean, but you’re taking on more operational complexity than Medusa. github.com

Platforms I’d be cautious about for freelance work

Magento / Adobe Commerce

• Very powerful.
• Very employable skill.
• But unless the client already lives in Magento, it’s often too much platform for a custom build.

PrestaShop

• Fine for traditional stores.
• Less attractive if your value proposition is "I build unique commerce systems."

A practical freelancer stack

If I were setting up a repeatable agency/freelance stack:

Modern custom builds

• Medusa
• Next.js storefront
• PostgreSQL
• Stripe/Adyen/etc.
• external CMS (Sanity/Contentful/Strapi)

Fast SMB builds

• WooCommerce
• custom plugin layer
• WP REST API/WPGraphQL
• managed WordPress hosting

Enterprise-ish builds

• Saleor
• Next.js
• custom integration services

For a developer whose differentiator is custom integrations, I’d probably standardize on Medusa first, WooCommerce second. Medusa lets you sell engineering capability; WooCommerce lets you ship quickly when the client mostly needs a store with a few custom touches. www.wpbundle.comwww.wpbundle.com

If your main business is building custom stores and integrations for clients, I’d shortlist Medusa, Shopware, and Saleor—with Medusa as my default pick for a freelance developer.

1. Medusa — probably the easiest for your use case

Medusa developer documentation

Medusa is particularly attractive if you're comfortable with TypeScript/Node.js. It is explicitly designed as a commerce platform plus a framework for customizations. You can add API routes, workflows, data models, modules, subscribers, scheduled jobs, and admin extensions. docs.medusajs.comdocs.medusajs.com

The architecture is nice for client work because integrations don't have to become a mess of overrides. Its commerce functionality is split into modules—products, orders, payments, fulfillment, inventory, pricing, etc.—and you can build your own modules and workflows around them. docs.medusajs.comdocs.medusajs.com

I'd choose Medusa if you typically build things like:

• ERP/PIM integrations
• custom pricing logic
• unusual checkout flows
• B2B functionality
• marketplaces
• custom fulfillment
• external subscription systems
• headless Next.js storefronts
• stores where the client's requirements don't fit a conventional ecommerce box

The big advantage for a freelancer is that you can build reusable modules/plugins and carry them between projects. docs.medusajs.comdocs.medusajs.com

2. Shopware — best if you want a mature ecommerce ecosystem

Shopware developer documentation

Shopware is probably the stronger choice if your clients want a full-featured ecommerce platform out of the box, rather than a commerce framework.

It's open source, self-hostable, API-first, and has both an app system and PHP-based plugins. Its plugins can make very deep changes to the platform, while its APIs/webhooks provide a cleaner integration mechanism. developer.shopware.com

It's built on Symfony/PHP, so if that's your stack, Shopware becomes especially compelling.

The downside: there's considerably more platform to learn. For a developer who just wants to create a highly customized store, Medusa generally feels less heavyweight.

3. Saleor — excellent if you want GraphQL/headless

Saleor documentation

Saleor is another very good choice if you're building modern headless commerce. Its core API is GraphQL, and it has explicit concepts for apps, extensions, custom data modeling, payments, shipping, marketplaces, and custom dashboard functionality. docs.saleor.io

I'd put it ahead of Medusa if your typical client says:

"We have a React/Next.js frontend and need an extremely API-driven commerce backend."

But for arbitrary backend customization, I find Medusa's modular architecture more attractive.

My recommendation for a freelance stack

I'd probably standardize on:

Medusa + Next.js + PostgreSQL + Stripe + your integration layer

and keep Shopware in your toolbox for clients who need a more established, enterprise-oriented ecommerce system.

The distinction I'd use is:

"I need to make the ecommerce platform behave differently." → Medusa

"I need a mature ecommerce platform with lots of functionality, but I need to customize it deeply." → Shopware

"The storefront is completely custom and the commerce backend should primarily be an API." → Saleor

If you're going to be doing 10+ client stores, I'd lean especially strongly toward Medusa because its modules/workflows/plugins give you a good foundation for building your own reusable integration toolkit. docs.medusajs.comdocs.medusajs.com

If your priority is “I’m a developer and need to build lots of custom integrations without fighting the platform,” I’d pick Vendure.

My ranking for freelance client work

Why Vendure stands out: its entire extension model is based around plugins. A plugin can add database entities, GraphQL queries/mutations, REST endpoints, event handlers, background jobs, custom fields, and integrations with external systems. It is built on NestJS, so if you're comfortable with TypeScript, the programming model is familiar. docs.vendure.io

For example, a client integration like:

Shopify/WMS/ERP → sync inventory → modify order workflow → add custom order fields → expose admin UI → process asynchronously

can live in a dedicated Vendure plugin rather than becoming a pile of hacks around the core.

Vendure also has strategy patterns for replacing built-in behavior without forking the platform—things like tax calculation, shipping eligibility, stock allocation, asset storage, etc. vendure.io

Vendure vs. Medusa

Medusa is the one I'd seriously consider alongside Vendure. Its architecture is also explicitly designed for customization: API routes → workflows → modules → database, with custom modules for third-party integrations. Modules can be reused between projects, which is particularly attractive for a freelancer building similar integrations repeatedly. docs.medusajs.com

I'd choose Medusa if you want to build your own reusable commerce building blocks and like its workflow/module architecture.

I'd choose Vendure if you want the least friction when modifying an existing commerce system. Its plugin system gives you a very direct way to add functionality while retaining access to the core's services, events, APIs, entities, and dependency injection.

For your specific business

If you're building stores for different clients, I'd lean:

Vendure → build a library of reusable plugins → deploy a customized configuration per client.

For example:

your-vendure-toolkit/
├── erp-sync/
├── shipping-provider/
├── custom-pricing/
├── loyalty/
├── crm-sync/
├── marketplace-sync/
├── custom-checkout/
└── client-specific/

That gives you a potentially nice freelance advantage: your integrations become reusable IP rather than one-off modifications.

If you're primarily a PHP/Symfony developer, I'd flip the recommendation to Sylius. If you're primarily Python/Django, I'd look harder at Saleor.

For a TypeScript/Node freelancer doing custom integrations, though, Vendure would be my first platform to evaluate in 2026. docs.vendure.io

If your priority is “I need to keep extending the platform for different clients without fighting the framework,” I’d put Vendure at the top of the list, with Medusa a very close second.

My ranking for a freelance custom-integration shop

1. Vendure — my pick for your use case

Vendure is particularly well suited to a freelancer building bespoke commerce backends.

Its extension model is essentially built around plugins. A plugin can:

• add/modify database entities
• add custom fields
• add GraphQL queries and mutations
• add REST endpoints
• interact with external systems
• subscribe to commerce events
• run background jobs
• replace core behavior through strategies

And it's all TypeScript + NestJS, so you're working with fairly conventional backend patterns rather than learning an ecommerce-specific extension language. docs.vendure.io

The particularly important bit for your business is that Vendure explicitly supports extending without forking the core, which makes upgrades much less painful. Its plugins also work the same way when self-hosted or on its cloud offering. vendure.io

For example, a client could need:

Shopify → ERP → Vendure → 3PL → custom pricing engine

You could make each integration a plugin, with events/jobs handling synchronization rather than hacking the ecommerce core.

Vendure even has a current guide specifically walking through building a CMS synchronization plugin, which is pretty representative of the sort of work you're describing. docs.vendure.io

2. Medusa — arguably better if you want maximum composability

Medusa is probably the other one I'd seriously consider.

Its architecture is extremely integration-friendly: API routes → workflows → modules → database. Third-party integrations are implemented through modules, and you can create your own modules for things like ERPs, CMSs, payment systems, fulfillment, etc. docs.vendure.iodocs.medusajs.comdocs.vendure.io

Its plugin system can package modules, API routes, workflows, workflow hooks, links, subscribers, scheduled jobs, and admin extensions, which is excellent if you're trying to build reusable components across multiple client projects. docs.medusajs.com

I'd choose Medusa over Vendure if your typical project looks like:

“The client has a bunch of external systems and we want commerce to be one composable service in the middle.”

I'd choose Vendure if it looks more like:

“The client needs an ecommerce system, but we're going to heavily customize the actual commerce behavior.”

3. Saleor

Saleor is very attractive if you want a GraphQL-first, headless architecture. Its ecosystem has explicit concepts for apps, extensions, dashboard customization, APIs, and self-hosting. docs.saleor.io

The tradeoff is that I find its extension model a little less natural for deep backend customization than Vendure's plugin model. It's particularly compelling when most custom functionality can live as external applications/services.

The important distinction

For your business, I'd evaluate platforms less on “how many plugins exist?” and more on:

Can I put arbitrary client-specific business logic inside the platform without modifying its source code?

That's where Vendure and Medusa shine.

For example, you might want to turn your common integrations into reusable packages:

my-commerce-stack/
├── vendure/
├── plugins/
│   ├── erp-sync/
│   ├── custom-pricing/
│   ├── shipping-provider/
│   ├── crm-sync/
│   ├── marketplace-sync/
│   └── client-specific/
└── storefront/

Then each new client becomes mostly configuration + a handful of custom plugins, rather than starting from scratch.

My recommendation: start with Vendure if you're comfortable with TypeScript/NestJS. Spend a day or two also prototyping the same integration in Medusa. If your integrations tend to be event-driven and deeply embedded in commerce behavior, I'd expect Vendure to win; if they're more like independent services stitched around a headless commerce core, Medusa may win. docs.vendure.iodocs.medusajs.comdocs.vendure.io

If you tell me what kinds of integrations you usually build (ERP, POS, shipping, subscriptions, marketplaces, custom pricing, etc.), I can give you a Vendure vs Medusa vs WooCommerce comparison specifically for a freelance agency workflow.

If your main criterion is “I need to build weird client-specific integrations quickly, repeatedly, and without fighting the platform,” I’d put Medusa at the top of the list.

My ranking for a freelance developer

Why Medusa stands out for your use case: its architecture is explicitly designed around custom modules, workflows, API routes, subscribers, providers, and admin extensions. You can package a whole integration as a reusable plugin and install it into another client's Medusa project. docs.medusajs.com

That matters a lot for freelancing. For example, you could build a reusable acme-erp-sync plugin containing:

• ERP integration/module
• product/order synchronization
• webhook subscribers
• scheduled jobs
• custom workflows
• API endpoints
• admin UI

Then reuse it across clients rather than maintaining a pile of copy-pasted modifications. Medusa specifically supports this plugin model. docs.medusajs.comdocs.medusajs.com

There's also a nice separation between modules and workflows: modules encapsulate integrations/data, while workflows let you compose business operations across modules. That is a good fit for things like “when order ships → update ERP → create accounting record → notify customer.” docs.medusajs.com

When I'd pick Bagisto instead

If you're a Laravel/PHP developer, I'd seriously consider Bagisto instead. Its core is built as modular Laravel packages, with repositories, model proxies, events, package development, and APIs intended for extension without modifying core. devdocs.bagisto.com

It's probably the more comfortable choice if your clients want a conventional ecommerce admin/store rather than a heavily headless architecture.

When I'd pick Sylius

Sylius is excellent if the projects are genuinely complex—custom pricing, unusual order lifecycles, B2B rules, multiple fulfillment concepts, etc.—and you're comfortable with Symfony. Its plugin architecture is deliberately designed to extend functionality without modifying core. academy.sylius.com

The downside for a freelancer is that I wouldn't call Symfony/Sylius the quickest learning curve compared with Medusa if you're already comfortable in modern TypeScript.

My practical recommendation

If I were building a freelance stack today:

TypeScript/React → Medusa
Laravel/PHP → Bagisto
Symfony/PHP + very complex commerce → Sylius

For custom integrations specifically, I'd start with Medusa. Its reusable-plugin model is unusually well aligned with the economics of freelancing: build an integration once, parameterize it per client, and carry it forward to the next project. docs.medusajs.comdocs.medusajs.com

If you tell me your preferred stack (Next.js/TS, Laravel/PHP, Python, etc.) and the kinds of integrations you usually build (ERP, shipping, PIM, marketplaces, subscriptions, POS, etc.), I can narrow it down to the best 2–3 options and explain the tradeoffs.

If your main business is building custom integrations for different clients, I’d pick Medusa.

My ranking for a freelance developer

Why Medusa stands out: its architecture is explicitly designed around modules, workflows, API routes and integrations. You can create a custom module for something like an ERP/CRM, use workflows to orchestrate it with orders/products, and package reusable functionality as a plugin. docs.medusajs.com

That is particularly attractive for a freelancer because you can build something once—say a Shopify → client's ERP sync—and turn it into a reusable module/plugin for your next client. Medusa explicitly supports custom third-party integrations and positions the platform as a middleware layer between commerce and external systems. docs.medusajs.com

When I'd choose the others

Sylius is arguably the strongest choice if you're a PHP/Symfony developer and expect extremely bespoke commerce logic. Its plugin system is mature and Symfony-native; plugins can extend the platform without modifying core code. academy.sylius.com

Saleor is excellent if your integrations are primarily external services talking to a GraphQL API. Its philosophy is deliberately to keep the core untouched and extend it through Apps, webhooks and API extensions. github.com

The tradeoff is that Saleor's model tends to push customization outside the core. That's fantastic for keeping upgrades clean, but if a client's requirements involve substantial changes to commerce behavior/data models, Medusa gives you a more direct framework for implementing those changes.

For your particular freelance use case

I'd lean:

Medusa → if you're primarily TypeScript/Node.js
Sylius → if you're primarily PHP/Symfony
Saleor → if you want API-first/headless and external apps doing most of the customization

If you're starting from scratch today, Medusa is probably the best "one platform I can learn and use for lots of clients" choice. Its modules and plugins are especially well aligned with building reusable integration components. docs.medusajs.com

If you tell me your preferred stack (Node/PHP/Python) and the kinds of integrations you typically build (ERP, PIM, shipping, marketplaces, subscriptions, etc.), I can narrow this down to the best 1–2 options.

If your main business is building custom stores and integrations for clients, I’d put Medusa at the top of the list.

My ranking for a freelance developer

Why Medusa: it's essentially a commerce framework rather than a rigid ecommerce application. Its architecture is split into API routes, workflows, modules, and a database layer, and you can create your own modules, workflows, API routes, links, subscribers, scheduled jobs, and admin extensions. docs.medusajs.comdocs.medusajs.com

That's particularly attractive for freelance work because you can build reusable integration packages once and carry them from client to client. Medusa explicitly supports reusable plugins containing modules, routes, workflows, hooks, subscribers, jobs, and admin extensions. docs.medusajs.comdocs.medusajs.com

For example, you could create a reusable:

• ERP integration module
• custom shipping provider
• B2B pricing module
• PIM synchronization workflow
• marketplace connector
• loyalty system
• custom checkout logic

…and install those pieces into different client projects.

Medusa vs. Sylius

I'd choose Sylius if you're a strong Symfony/PHP developer. It's exceptionally flexible because it is built as a Symfony-based framework, with plugins designed to extend functionality without modifying core code. academy.sylius.com

But if you're primarily a JavaScript/TypeScript developer, Medusa is the easier recommendation. Its Node/Postgres architecture and module system make it particularly natural for building custom integrations. docs.medusajs.com

Where Saleor fits

Saleor is probably my second choice if you prefer Python + GraphQL. It's extremely integration-friendly: GraphQL-native, headless, with a large webhook surface and extensible dashboard. saleor.io

The tradeoff is that Saleor's extension philosophy is more external/app/composable-system oriented, whereas Medusa lets you get quite deep into the commerce application's own modules and workflows.

One important distinction

If by "easiest to extend" you mean "I want to change virtually anything in the business logic", I'd choose:

Medusa → Sylius → Saleor → WooCommerce

If you mean "I want to rapidly add integrations that already have plugins", the ranking changes considerably:

WooCommerce → Medusa → Saleor → Sylius

For a freelancer doing custom client integrations, though, I'd favor the first interpretation.

My pick: Medusa. It gives you a reusable framework for turning custom client requirements into modules/plugins rather than repeatedly fighting an existing monolithic ecommerce application. docs.medusajs.com

If you tell me your usual stack (e.g. Next.js/TypeScript, Laravel/PHP, Python/Django) and the kinds of integrations you build (ERP, shipping, payments, PIM, marketplaces, etc.), I can narrow it down to the best 1–2 platforms for your agency workflow.