The ecommerce industry experiences growth year-on-year, and in 2023 digital retail is more competitive than ever before.

In the race to stay ahead, businesses utilizing ecommerce as part of their strategy should be increasingly looking toward technology for solutions to common sales challenges.

The rise of Composable and Headless Commerce as a viable solution to delivering high-quality, impactful customer experiences shouldn't be overlooked, as they offer a powerful advantage over alternative approaches.

In this article, we'll discuss both Composable and Headless Commerce, and address the all important questions:

What's the difference? How to they compare? And where should they be utilized?

Composable vs Headless Commerce: How do they compare?

Let's start by diving into an official definition for each development approach:

Headless Commerce



Headless Commerce involves the decoupling of an ecommerce backend from the client-side storefront.



At a higher level, this approach aims to create a distinct separation between the two core components of any ecommerce system: the backend (for managing products, orders, business logic, and operations), and the frontend (the user interface through which shoppers interact and make purchases).



From a technical point of view, Headless Commerce provides an advantage because the two key components to the ecommerce application can utilize appropriate technology for the tasks at hand.



Popular backends for Headless Commerce in 2023 include Shopify, BigCommerce, Magento, and CommerceTools.



As for the storefront, libraries and frameworks built on JavaScript are commonplace with Headless Commerce, due to their ability to achieve dynamic user-experiences and rich customer journeys. Such frameworks include Next.js, Gatsby, Remix, Angular, and Vue. 


Composable Commerce



Composable Commerce is a new development approach for ecommerce stores that heavily leverages Headless Commerce as key part of the stack.



Based on the MACH architecture (Microservices, API-first, Cloud-native, and Headless), composable commerce aims to modernize the ecommerce stack through the development approach itself.

Composable commerce uses a modular approach to architecting the tech stack, opting for a heavy utilization of micro-services and integrations, rather than a bloated central codebase.

At a higher level, utilizing MACH architecture provides businesses with greater technical agility, enabling them to respond to changes within their industry or progressions in technology at a faster pace.

Composable Commerce aims to address business requirements with best-fit technology at every turn, in contrast with a more monolithic, all-in-one approach.

With Composable Commerce, an application's architecture will involve the use of many third-party technologies, each hand-selected for their particular capabilities to satisfy the business objectives where applied.

A key component to a composable approach is the utilizing of headless architecture by design; and this is because headless architecture serves to strengthen a business's ability to respond with agility to industry changes and the adoption of emerging technology, this fitting directly into the composable model. 

How does a Monolithic Approach Differ from Composable + Headless?

Developers use the term "monolithic" in the context of ecommerce to refer to the traditional approach of leveraging an all-in-one platform to serve a business's e-commerce needs.

Typically, this would be a single application that would service both the frontend and backend of an ecommerce store. The term was coined primarily as a way to create a distinction between the traditional approach, and newer, more progressive approaches (think Headless, Composable).

Headless and Composable architectures utilize a variety of technologies within their stack to service different parts of the overall application, applying more appropriate tech to the needs of each layer. For example, with both Headless and Composable Commerce, the presentation layer will most often be served by a performant JavaScript framework which caters specifically to the needs of the storefront.

In contrast, a monolithic (or traditional) approach to ecommerce would see the backend application also handle the building and rendering of the frontend, directly from the same codebase.

Monolithic ecommerce applications can be seen as all-in-one solutions, which cover the full breadth of the ecommerce architecture for a particular project or build, but the biggest drawback is perhaps their limitations in control.



A monolithic architecture does bring some benefits, but these are few and far between, particularly for digital retailers who aim to create impactful, engaging, and highly-custom user experiences on the frontend.

On the flip side, a monolithic approach can also serve to ease some of the barriers smaller businesses face to adopting a composable or headless approach.

With a headless or composable model, the decoupled storefront will make requests to the backend via APIs in order to source data regarding products, categories/collections, and anything else required for the purposes of populating frontend pages.

Particularly with a composable architecture, the frontend will often pull data from multiple backends, as is commonly the case in a headless approach — where products are sourced from a best-fit ecommerce backend, and brochure pages are sourced from a best-fit CMS.



In contrast, a monolithic application would make direct queries to the database from the frontend. 



Headless or composable frontends have the ability to source data at different times in the application's lifecycle.

For pages or products that don't change very often, the data can be fetched at build time, which essentially means that they don't require any (or as many) requests to be made to the backend APIs on the client-side (when users visit the page).

In a really lean setup, it's possible to completely omit live data fetching for pages that don't require it (i.e. parts of the store that don't change often), which means that shoppers will experience blazing-fast load times in the browser (since no additional requests to the backend are being made for simply loading a page).

In a monolithic world, typically the server would experience multiple database requests to load a single page, which would grow cumulatively as concurrent traffic increases.

Composable and headless architectures have the ability to handle this gracefully, right out-the-box (rendering methods), whereas for monolithic architectures it will usually involve a struggle of installing and configuring multiple extensions in order to achieve a desirable level of caching, which still doesn't provide full control over exactly which parts of a page are cached (pre-rendered) and which are not.

The modular architecture that Composable Commerce provides, and the fact that Headless Commerce implementations can make use of various rendering methods, which are completely within the developer's control, means that these progressive ways of developing ecommerce storefronts can provide far superior options for optimization.


 

So, what separates Composable from Headless Commerce?

Composable and Headless Commerce share many similarities, but fundamentally it's the approach to architecture and implementation that separate the two.

A composable approach to ecommerce architecture focuses primarily on the business needs and objectives, and aims to marry technology with specific elements within the stack, even down to individual front or backend functionalities.

This contrasts with many traditional approaches, where only a few – or even just one – technology is utilized to serve the entire stack.

A monolithic approach would see the majority of the ecommerce architecture served by the same application, with a few select integrations for particular functionality, such as a third-party payment gateway, some custom JavaScript snippets to enhance frontend functionality, and perhaps an analytics tracking code installed on the frontend.



In contrast, a composable approach will utilize a much larger variety of technologies or services overall, implementing best-fit tech for each major component of the stack, or each major functionality.

One simple example is frontend search. With a composable setup, the search functionality may be provided by a specific best-in-class search provider, rather than connected directly to the ecommerce backend.

One popular choice, for instance, is to leverage Algolia for frontend search in contrast to relying on the backend using database queries.

Frontend user authentication may also use a specific authentication provider such as Auth0 or Firebase, as these tools may be better positioned to achieve the business requirements for authentication, compared with sending auth requests or storing user data directly in the ecommerce backend.

Various other features and functionalities, such as out-of-stock notifications, email delivery, order fulfillment and automated label printing are all areas where best-fit technology would be selected as part of a composable approach.

This is quite a contrast from a monolithic setup, which would typically utilize the same application to deliver the bulk of the required functionalities.

With composable, there doesn't need to be a central application or system, because each layer in the stack is architected to work harmoniously together, passing data freely between them.

This flexibility enables businesses to leverage the most appropriate technology for each part of the build, rather than struggling against a single application that has a set way of doing things.

This newfound freedom allows online retailers the ability to control how their ecommerce stack behaves, and architect a highly custom implementation that meets the specific requirements of the business.

There is some overlap between Composable and Headless Commerce, but the primary difference is that a headless approach does not dictate such a highly modular architecture as composable.

In general, headless architectures are generally more focused on decoupling of the ecommerce frontend and backend, and this creates a degree of overlap in the selection of best-in-class services for other frontend functionality such as authentication and search.

However, headless builds are not necessarily approached with the same level of modularization as composable, and don't define MACH as a core building block.

In reality, many headless ecommerce builds likely leverage a large degree of composability, piecing together various building blocks to architect a high-performance stack. But this doesn't form a core principle of a headless approach. 

For instance, an ecommerce store running on WordPress with WooCommerce can indeed be rearchitected as a headless build, through decoupling the frontend interface from the WordPress backend, and sourcing data via APIs.

This achieves a level of modularization in the stack, as a better-fit technology has been selected for delivery of the frontend experience. However, this alone doesn't make the build "composable"; the frontend has rather just been decoupled.

Headless decoupling of an ecommerce frontend can often be seen as the first step in a journey toward composable commerce.

We find that many of our clients choose to go composable after experiencing the benefits that a decoupled frontend can offer, in terms of superior flexibility and a more intuitive, impactful customer experience.