Making personalization simple in the composable era with data-driven CMS

For today’s digital agencies, delivering high-performing, lead-generating websites isn’t just about building fast and flexible front-ends. It’s about creating truly adaptive experiences. Tech leads and product owners are increasingly expected to implement personalization and A/B testing to deliver data-driven content strategies that move the needle for their clients.

Composable architectures promise freedom of choice, but assembling the right stack is a growing challenge. The challenge is how to keep it lean, affordable, and easy to maintain. Many teams default to multi-system setups for data-driven content strategies, combining a headless CMS with a CDP and a personalization engine. While powerful, this model can quickly become complex, expensive, and hard to iterate on.

This article explores a smarter alternative: data-driven headless CMSs that bring content and data together in one platform. For tech leads looking to streamline their architecture, move faster, and deliver more personalized lead-gen experiences, without the overhead, this new generation of CMS offers a compelling path forward.

You’ve probably heard it a dozen times by now: “We’re moving to a composable platform.”

Sounds modern. Ambitious. Strategic.

But what many agencies and clients don’t say out loud is that they’re often building “Frankenstacks”; complex stacks made of multiple best-of-breed systems, patched together in the hope of creating an easy-to-use and high-performing digital solution.

When Mary Shelley wrote Frankenstein, she told a story about creating a powerful being made from parts that didn’t quite fit. The result was unpredictable and hard to control.

Today’s digital experience world faces a similar dilemma. Agencies and clients want a complete solution, but often end up with systems that are clunky and fragile, slowing teams down and frustrating users.

In 2025, the question isn’t just “composable platform or not?” It’s about avoiding the Frankenstein trap of multi-system chaos and instead delivering agile, data-driven experiences that truly meet client needs.

Composable platforms promised a bold new approach: choose best-of-breed tools to deliver data-driven content strategies, a headless CMS, CDP, personalization engine, analytics, and more, and combine them into one powerful composable stack.

On paper, this approach sounded ideal. Agencies and brands could select exactly what they needed and build a tailored solution. But in practice, the promise hasn’t fully materialized.

Composable stacks turn into a Frankenstein's monster, a digital Frankenstein made up of multiple vendors, each with its own interface, data model, and roadmap.

While each tool may perform well on its own, integrating them becomes a constant challenge. Agencies must manage multiple vendors, coordinate across different systems, and handle fragile integrations. Every update or campaign introduces risk, requiring syncing data, debugging APIs, and testing every moving part.

Teams often spend more time connecting tools than creating experiences, and still end up supplementing the stack with additional systems to fill capability gaps.

This growing web of tools needs constant development, coordination, and maintenance. For agencies, that means longer projects, higher risks, and difficulty showing clear value.

What was meant to be agile ends up fragile.

Here’s what a typical composable stack looks like today:

• A headless CMS for managing content
• A Customer Data Platform (CDP) for managing user data
• An analytics solution
• A personalization engine
• A/B testing software
• An omnichannel delivery layer
• And custom code or middleware to connect it all together

Each tool on its own is powerful, but together they create a complicated ecosystem. Managing this stack means dealing with multiple vendors, syncing data between disconnected systems, and constantly maintaining fragile integrations. It demands a lot of development work, inflates SaaS costs, and turns even small updates into big projects.

This is not what clients are looking for in 2025.

They expect faster, more flexible solutions, but instead face isolated systems, inconsistent user experiences, and growing technical debt. Ironically, the very complexity they were trying to avoid is now built into the foundation of their digital stack.

While agencies debate platforms and architectures, clients are focused on something else entirely: outcomes.

In 2025, clients want fewer tools, not more. They want seamless workflows, real-time insights, and the power to launch campaigns quickly without logging into multiple systems.

What they really want is:

• Speed. Fast time-to-market with real-time optimization
• Clarity. One platform to manage content, data, and performance
• Control. Marketing teams are empowered to test and launch without developers
• Personalization that actually works. Not just basic segmentation, but real-time, data-driven targeting that improves results.
• Lower overhead. Simpler tech stacks, fewer costs, faster execution

This shift is driving demand away from complex composable stacks toward simple composable stacks that make digital experiences simpler and smarter.

This shift in client expectations has given rise to the next generation of CMS platforms: data-driven CMS solutions that blend the flexibility of headless architecture with built-in intelligence for personalization, testing, and optimization.

Unlike composable stacks made up of multiple systems, data-driven CMS platforms integrate content and data in one unified environment. There’s no need for a separate personalization engine, CDP, or A/B testing tool, the intelligence is built right in.

By embedding real-time segmentation, segment-based personalization, and omnichannel delivery directly into the CMS, agencies can create adaptive experiences without complex development or fragile integrations. Content becomes dynamic and responsive by default, not after weeks of orchestration work.

This approach gives agencies a clear advantage: faster launches, quicker iterations, and precise personalization — all managed within a single platform. Fewer components mean less technical debt and greater control for marketing teams, delivering the agility modern businesses need.

The differences between a typical multi-system solution and a modern data-driven CMS are clear and critical. While both aim to enable personalized digital experiences, only one delivers speed, simplicity, and intelligence without unnecessary complications.

Here’s how they compare:

For agencies, the takeaway is clear.

Composable stacks offer flexibility in theory, but come at the cost of complexity, slower delivery, and higher risk. Data-driven CMS platforms simplify execution, empower smaller teams, and accelerate time-to-value by combining content and data work together in one system.

Agencies have always been trusted to make sense of digital complexity. But in 2025, leadership isn’t about stitching together more tools; it’s about simplifying, focusing, and delivering better outcomes.

Clients aren’t asking for more systems. They’re asking for clarity, speed, and measurable results. That’s why forward-thinking agencies are moving away from taking the risks of Frankenstacks and embracing smarter, unified foundations like data-driven CMS platforms.

The path forward is clear, but it requires intentional choices:

• Simplify your stack Help clients cut down on too many tools by picking CMS platforms that include personalization, testing, and analytics built-in.
• Invest in data-driven workflows Choose platforms where data is central. Real-time insights, user targeting, and testing should be part of the system, not added on later.
• Reposition your agency Don’t just be an implementer of tools. Be a strategic partner who delivers speed, focus, and business impact. Clients value partners who reduce complexity and accelerate growth.
• Empower your teams Adopt modern development frameworks and headless architectures that match your team's skills and reduce operational drag. When the tools are better, the work gets better and faster.

By embracing these principles, agencies can finally leave the Frankenstein era behind and build unified, high-performing digital experiences that exceed client expectations.

Making thoughtful choices today positions your agency to lead, not just keep up, in a rapidly evolving market. The future belongs to those who simplify, innovate, and deliver real value—starting now.