The eCommerce landscape is experiencing a fundamental shift. While traditional platforms, with their promise of quick deployment and extensive feature sets, dominated the market for years, a growing number of businesses are discovering the hidden costs and limitations of these solutions.
We’ve recently had the opportunity to pick the brain of Nick Gellner, COO and co-founder of Medusa, which is the number one open-source commerce project on GitHub. During our talk, we explored how modular open-source eCommerce platforms address the key pain points that have long plagued enterprise commerce.
Here are the key takeaways.
The hidden costs of traditional commerce platforms
“Can you give us access to the code, so we can see what’s inside?” This question, intimately familiar to Cloudflight’s business consultants, represents one of the most common challenges businesses face when trying to evolve their ecommerce operations. The answer is almost always the same: it’s simply impossible. Traditional eCommerce platforms are protective of their code and are very reluctant to let customers peek under the hood.
This scenario plays out countless times across enterprises worldwide. Companies invest heavily in eCommerce platforms, only to discover that they’re locked into systems they don’t control, can’t modify, and struggle to migrate away. The result? Businesses face continuity risks, vendor dependency, and mounting frustration as their needs evolve faster than platform capabilities.
Traditional SaaS platforms compound these challenges with their platform fees and additional costs for apps and integrations. These expenses can quickly escalate, especially for high-volume businesses, creating an ongoing financial burden that grows with success.
Perhaps the most significant hidden cost is time. When businesses need to implement custom workflows, integrate with existing systems, or build differentiated customer experiences, traditional platforms often become bottlenecks rather than enablers.
The statistics are telling. According to Medusa’s research, if you compare B2B platform requirements from three years ago to today, approximately 80% of the desired functionality needed to be customized or built from scratch on traditional platforms. While this percentage is improving as platforms mature, the fundamental limitation remains: businesses are constrained by what their chosen platform allows, not what their customers need.
Modular commerce: the Lego block approach
The emergence of modular open-source commerce platforms represents a paradigm shift in how businesses approach eCommerce architecture. Unlike traditional monolithic solutions, platforms like Medusa take what Nick Gellner describes as a “Lego brick approach” to commerce functionality.
What makes Medusa different from SaaS platforms
The key differentiator lies in true architectural flexibility. Over time, legacy solutions like Magento have moved significant features under secondary licenses or forced users toward enterprise solutions like Adobe Commerce. On the other hand, newer open-source platforms are taking a radically different stance. “All commerce features we build will be open-source,” explains Gellner. “If they don’t start as open source, they will always become open source.”
This modular architecture means that every component, for example the cart module or customer account, can be independently replaced or customized. If your business has an existing enterprise resource planning (ERP) system for pricing logic or a product information management (PIM) system, you can easily replace Medusa’s default modules with direct connections to your existing solutions.
The implications are profound. Instead of forcing your business processes to conform to platform limitations, you can adapt the platform to support your unique workflows and requirements.
The football club case study
A perfect example of this flexibility comes from an unexpected source: a football club using Medusa to solve a problem that has frustrated sports fans for years. Anyone who has tried to purchase sports tickets online knows the frustration of being unable to buy merchandise and tickets in the same transaction. These purchases require separate systems, one for eCommerce and another for ticketing, that operate independently.
With Medusa’s open architecture, this football club can inject tickets from their separate ticketing system directly into the commerce platform’s cart. Customers can now purchase jerseys and match tickets in a single, seamless transaction. This type of cross-system integration, which would be nearly impossible on traditional platforms, becomes straightforward when you have free access to the underlying commerce logic.
This case illustrates a broader principle: when platforms are built for extensibility from the ground up, seemingly impossible integrations become routine customizations.
The build vs. buy decision gets a third option
The traditional software procurement process has long presented businesses with a binary choice: either build custom solutions from scratch or buy existing SaaS platforms. This decision typically weighs development time and costs against platform limitations and ongoing fees.
However, the rise of AI-assisted development is fundamentally changing this equation because development teams are now iterating faster than ever before. What previously required weeks of custom development can now be accomplished in days or hours with AI assistance. This acceleration makes the “build” option increasingly attractive, especially when starting with a robust open-source foundation.
Open-source commerce platforms occupy the sweet spot in this new paradigm. They provide 70-80% of required functionality out of the box, which is a major surprise to many who associate open source with extensive custom development requirements. This foundation eliminates the need to build core commerce features while preserving the flexibility to customize and extend functionality as needed.
The cost advantages are substantial. Open-source platforms eliminate platform fees, revenue sharing on gross merchandise value (GMV), and the need for expensive third-party integrations. The only costs are infrastructure hosting and development resources, which are expenses that businesses control directly.
Perhaps most importantly, this approach delivers what Gellner estimates as “two to three times faster time to market” compared to traditional platforms, especially when custom integrations and workflows are required.
The UX revolution in B2B commerce
The B2B commerce experience is undergoing a dramatic transformation. Five to ten years ago, B2B purchasing interfaces were, in Gellner’s words, “very cumbersome, a lot of clicking around, a lot of trying to build a sort of an Excel sheet copy of a webshop.” These systems focused purely on order processing, with little attention to user experience, marketing features like upselling opportunities, or conversion optimization.
Today, B2B buyers expect consumer-grade experiences. The bar has risen to match D2C standards, where UX and UI are critical differentiators. This shift isn’t just about aesthetics. It has a real business impact as well. B2B buyers are now willing to pay premiums for products that are easily accessible and simple to purchase through online channels, recognizing the cost savings these efficient processes deliver.
This transformation is driving demand for commerce platforms that can deliver sophisticated, customized user experiences while seamlessly integrating with complex B2B tech stacks. Traditional B2B organizations typically operate multiple systems: ERP platforms, PIM systems, accounting software, payment gateways, and other specialized industry tools. The commerce platform must orchestrate all these systems while presenting a unified, intuitive interface to buyers.
The challenge intensifies when businesses need to create differentiated experiences across multiple customer segments, regions, or product lines. Monolithic platforms force businesses to follow pre-configured flows, but modular platforms enable complete customization of customer-facing experiences while maintaining integration with backend systems.
AI and open source: the perfect storm
The convergence of artificial intelligence and open-source architecture is creating unprecedented opportunities for rapid commerce development. This synergy works because AI development tools perform best when they have full access to underlying code and system architecture, which is exactly what open-source platforms provide.
Gellner shares a compelling example: “One of the examples we’ve seen is being able to, for instance, just prompt ‘I want product reviews.’ That’s not built into Medusa. But because the platform is open and modular, the AI goes in and creates another module that has the name Product Review and builds the business logic that you expect.”
This capability extends beyond simple feature additions. AI can create custom modules, modify existing workflows, and even generate front-end implementations. All of that because it has complete access to the platform’s architecture. Closed systems, by contrast, severely limit AI’s ability to create meaningful customizations.
The implications for development velocity are staggering. Teams can now implement complex commerce features through natural language prompts, dramatically reducing the time from concept to deployment. This acceleration makes custom commerce solutions increasingly viable for businesses that previously couldn’t justify the development investment.
Looking ahead, it’s not difficult to imagine scenarios where business users can create sophisticated B2B commerce platforms by simply describing their requirements: “Build me a B2B commerce platform on Medusa. I’m selling 100,000 parts, and here’s the product file.” Such capabilities are likely to emerge faster than most anticipate.
Key takeaways from our Medusa deep dive
Our conversation with Nick Gellner revealed several insights that challenge conventional wisdom about open-source commerce platforms:
The 70-80% rule: Contrary to expectations that open source requires extensive custom development, businesses typically find that modern platforms like Medusa provide 70-80% of required functionality out of the box. This includes advanced features like multi-location inventory, regional configurations, gift carding, and sophisticated promotion engines.
True modularity: The ability to replace individual platform components with existing business systems represents a fundamental architectural advantage. Rather than forcing businesses to adapt their processes to platform limitations, modular systems adapt to business requirements.
Rapid implementation: The most complex Medusa implementations typically complete within six months, compared to the one-to-two-year timelines common with traditional platform migrations. This speed comes from the platform’s ability to integrate with existing systems rather than requiring wholesale replacements.
Cost predictability: With no platform fees, revenue sharing, or mandatory third-party integrations, businesses gain complete control over their commerce technology costs. This predictability becomes increasingly valuable as transaction volumes grow.
Future proofing: As AI continues to accelerate development capabilities, open-source platforms are uniquely positioned to leverage these tools for rapid feature development and customization.
Watch the full conversation
This article provides just a glimpse into the comprehensive discussion about the future of open-source commerce. The complete webinar includes detailed technical discussions about modular architecture and implementation strategies, as well as predictions about how AI will reshape eCommerce development over the next five years.
For businesses evaluating their eCommerce platform options or considering a migration from traditional solutions, the full conversation offers valuable insights into the practical considerations and strategic advantages of open-source commerce platforms.
The webinar also explores specific use cases, from subscription businesses to digital product marketplaces, demonstrating the versatility and power of modular commerce architecture in real-world applications.
Make sure to listen to the full webinar here.