Composable web architecture: a promise of agility or underestimated complexity?
Technical Director
Headless CMSs and composable architectures are attracting an increasing number of businesses. Promoted as the path to greater agility, scalability and omnichannel experiences, they are becoming a key talking point among software vendors and integrators. However, without a clear product vision or robust technical governance, the promise of agility can quickly turn into costly complexity.
The CMS is no longer the core
About ten years ago, a CMS was more than enough to cover most needs: publishing content, managing a few forms, running a blog. Today, the reality is quite different. Businesses want a marketing website capable of communicating with an extranet, feeding data to a mobile app, integrating an e-commerce engine and exchanging data in real time with a CRM. In this context, the CMS is no longer the centre of gravity of the system. It becomes just one component among many, connected to a range of services via APIs, and its value depends on the ability of the overall ecosystem to function coherently.
Freedom, yes… but with conditions
When designed methodically, a composable architecture offers undeniable benefits. It allows each component to be adapted independently, enables evolution without having to rewrite everything, and naturally lends itself to multi-channel experiences. It is a driver of scalability and technological independence that can transform a project. However, this freedom comes at a cost. The more building blocks there are, the more points of failure there are. Every integration must be maintained, and teams must be aligned both technically and functionally. This requires rigorous technical governance, a clear product vision and strong DevOps skills. Without these foundations, the architecture that was meant to simplify things becomes a constraint.
The risk of over-engineering
The main pitfall lies in adopting a composable approach out of habit or simply because it is fashionable. Too many simple projects become unnecessarily complex, with back-end systems that prove unmanageable for editorial teams and costs that spiral out of control over time. A composable architecture proves its worth when addressing multiple channels, designing a highly personalised front-end experience, or supporting a long-term digital strategy. However, it proves counterproductive in the case of a traditional editorial website without an in-house technical team, or when time and budget constraints mean that simplicity must be prioritised.
Lessons learnt from real-world experience
Experience shows that successful projects share several common features. They are based on a clear technical framework established from the outset, a precise mapping of workflows – content, products, users – and a deployment strategy designed to stand the test of time. Conversely, projects that encounter difficulties are often those where the choice of a headless approach was not sufficiently justified by the requirements, where the editorial dimension was underestimated, or where technical debt on the front-end side ended up placing a heavy burden on maintenance.
Composable: a philosophy above all
Composable should not be seen as a miracle technology, but as an architectural philosophy. Each building block must be designed to be replaceable, interoperable and orchestrated within a framework of overall consistency. It is a decision that must be aligned with business needs, available resources and project ambitions, not a choice dictated by trends or the desire to impress a committee. A sustainable architecture is not one that shines on the day it goes live, but one that continues to evolve and serve the business five years later.