What is a Composable CMS?

Composable web architecture is a relatively recent development. This short guide outlines what it is and explains how it relates to Headless Content Management Systems (CMS) like Contento.

Alan Gleeson - CMO Contento

Alan Gleeson

Co-Founder / CEO

January 29, 2024

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7 mins read

Composable CMS : Group of people around a laptop

Composable CMS - An Introduction

When it comes to software the concept of composability is not a new one. Some claim that Jonathan Murray (ex-EVP & Chief Technology Officer Warner Music Group) coined the phrase as far back as 2013 in his Composable Enterprise blog. More recently in 2020 a Gartner Keynote boldly declared - The Future of Business Is Composable which led to increased interest in the concept.

While the contexts vary from business organization to software development to website management the core idea is a simple one. This notion of modularity or ‘building blocks’, as distinct from an “all-in-one” approach which had been the default approach for many years.

Many of the top content management system (CMS) vendors are updating their products to offer their CMSs with a composable architecture combined with JavaScript as the primary language. This is often called a headless or SaaS-only CMS, which can be accessed via an API or microservice. This vastly differs from the traditional CMS platform, which includes the delivery layer, whose primary function is creating your webpage with the content before it leaves the web server. 

— Source: Lance Farquhar, Velir

Composable, thus refers to an approach that relies on different elements or modules that are interchangeable, and where APIs are used to manage the various components. 

Headless and composable are not interchangeable concepts. Products are headless; architectures are composable. The difference is that headless is a tactic and composable is a strategy.

— Source: Adam Conn

When it comes to websites it equates to a Headless CMS as distinct from a traditional or monolithic CMS like WordPress.With a Headless CMS, the front-end and the back-end are decoupled (or separated) so the back end acts as a content repository, and the content can be thus ‘fed to multiple heads’ be they websites, mobile apps, or billboards. 

The following article outlines the benefits of Headless CMS in more detail.

Composable CMS Architecture

A composable architecture refers to a design approach where your senior developers rely on reusable best-of-breed components (and thus vendors) connected via APIs to custom-build a cohesive system. This approach can speed up the development process which serves to reduce the overall development cost (although more senior devs will need to be involved which pushes cost up).

The primary benefits of a composable architecture according to Netlify are:

  • Flexibility

  • Optionality

  • Efficiency

  • Scalability

  • Site performance

  • Security and low-risk

  • Faster time-to-market

  • Cross-team collaboration and autonomy

— Source: Netlify 

Again these benefits align with the advantages outlined above as well as the benefits of a Headless CMS or Jamstack architecture where again modularity is at play.

Advantages of a Composable CMS

So what are some of the benefits of a composable approach? In many ways, the advantages mirror those of Headless.

  • By adopting a modular approach you can select best-of-breed tools and applications to enable you to deliver on your goals. 

  • Taking performance as an example - a composable approach helps you enjoy the performance optimization of Headless architecture.

If you can prerender high-traffic content during a build step, you’ll remove database connections and minimize the number of needed requests when serving a page. This will significantly speed up the site.

— Source: Netlify

  • You are not locked into an all-in-one solution with the inherent limitations of such an approach. This inherent flexibility means you can avoid vendor lock-in and swap modules in and out as you see fit, without causing major issues.

  • It also naturally lends itself well to a more scalable and adaptable approach enabling you to act more quickly.

  • While there are more points to attack, with a composable approach, bringing down one of those enterprise-grade services will not bring down the entire system.

Leading Digital Experience Strategy Consultant, Mark Demeny, outlines the following key advantages of composable:

  • More speed through discovery

  • Greater agility through modularity

  • Better leadership through orchestration 

  • Resilience through autonomy

Composable systems and architectures are made up of technologies with capabilities that enable those key pillars. You can be “headless” without being “composable” if those systems (and what you eventually assemble) do not easily enable teams to fully accomplish discovery, modularity, orchestration, and autonomy. An example of a headless CMS that would be “more composable” is one that allows you to easily export your content models and more advanced elements such as workflows or user and group permissions. The more you can do via APIs and script – the more likely you can easily interconnect and automate processes or change systems.

— Source: Mark Demeny

In short, a composable approach offers flexibility and scalability and is thus best suited for those looking to optimize their architecture. 

Disadvantages of a Composable CMS

So what are some of the disadvantages of a composable approach?

  1. The flip side of the inherent flexibility is that you are introducing more complexity, and thus more development and maintenance costs. 

  2. The elegance of an all-in-one solution is replaced with a marriage of different solutions. Different solutions mean different billing arrangements and an increased admin overhead.

  3. There can also be diagnostic issues when something goes wrong - which ‘part of the solution’ (or more likely parts plural are likely to be at fault?). It is a lot easier to diagnose issues when dealing with just one solution.

  4. In the context of a website, it is thus more appropriate when the senior developer managing the site is experienced and is also familiar with a range of different applications, systems, and frameworks. Naturally, experience comes with a cost, which typically means the ongoing development and maintenance costs are higher than with a more traditional approach e.g. using WordPress as the CMS.

As with many of these decisions, the context is everything. The advantages of composable are compelling for the correct use case, and thus the danger is adapting it in a situation where it is not a good fit. Be that because of the lack of internal resources or the fact that an all-in-one solution is a better fit for a particular client. 

Want a bespoke website? Then a composable or headless CMS-backed approach is the optimal route.

Composable CMS and Headless

When it comes to Headless CMS-backed websites the benefits of reusable components are compelling. In many ways, a Headless CMS is a by-product of a wider philosophy or strategy of the company. Are you API-lead where you look to pair best-of-breed solutions together or are you favoring an all-in-one approach where you rely on one vendor? 

The traditional CMS approach synonymous with WordPress websites remains extremely popular and makes sense in many contexts. However, for those looking for bespoke custom website builds, where performance optimization is a key requirement, then marrying disparate modules or components together makes a lot of sense, especially given the API capabilities of the various technologies at play.

Composable web architecture, or the decoupling of the frontend of your tech stack from the backend, has emerged as the preferred alternative to monolithic architecture, with 75% of respondents having built solutions with composable architecture in the past year.

Teams that have adopted composable web architecture are seeing tangible business results, including cost savings (37%), faster time-to-market (48%), higher productivity (58%), noticeable increases in website performance (48%) and greater ability to customize and personalize customer experiences (43%).

“It’s becoming increasingly clear that monoliths have fallen behind the world’s rapid pace of innovation,” said Matt Biilmann, co-founder and CEO of Netlify. “As the web is revolutionized by technology like AI, the time for business leaders to rethink their web architecture is now. Composable architecture offers the speed, freedom, scalability, and performance that every business is seeking.

— Source: Netlify: The State of Web Development (previously the Jamstack Community Survey)


In summary, while we may be bamboozled by terminology, the concept of a composable or modular approach is closely coupled with the Jamstack methodology and the use of a Headless CMS to power a website. The inherent advantages of these all stem from the advantages deriving from a more flexible scalable approach that favors best-of-breed over all-in-one.

In this composable content era, static messages and one-size-fits-all websites are a thing of the past. Today, content is a dynamic, living core of the business strategy. It's an era where highly personalized, context-specific experiences are the norm, and content is expected to adapt fluidly across all digital touch points.

This shift demands agility and flexibility in content creation, management, and distribution—a single source of truth that can be tailored to fit a variety of contexts and experiences.

— Source: Eric Nation (Operation Nation)

Alan Gleeson - CMO Contento
Alan Gleeson

Co-Founder / CEO

Alan Gleeson has 15+ years extensive B2B SaaS experience working with several VC backed Startups & Scaleups in the UK, US & Ireland.

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