Conversion Optimization

What I Think Every Digital Agency Should Know About Combining a CMS and Optimization Tools

Jouko Huismans
CEO @ Prepr
Read time: 8 min

In my work, I interact with many agencies daily, which gives me a unique perspective on their happenings. I observe their enthusiasm for creating exceptional experiences, but also their frustration of not always having the best solution that creates value for their customers, primarily due to inadequate optimization tools. I'd like to share these frustrations, the issues with these tools, along with a potential solution: a conversion-centric Headless CMS. Which could be particularly beneficial for medium-sized projects.

Passion for creating exceptional digital experiences

In my conversations with countless digital agencies, one thing stands out: the sheer passion for creating exceptional digital experiences. They are driven to deliver results that not only engage audiences but also drive conversions.

To build these exceptional customer experiences, you require a combination of several tools. Typically, the process begins with a headless CMS for managing and publishing content. However, you'll soon realize that just publishing content is no longer sufficient nowadays. It’s about making an impact. This is where optimization tools for A/B testing and personalization come into play. These tools are crucial for fine-tuning content to match the preferences and behaviors of your clients’ audience.

But here's the thing I’ve noticed, despite all this drive and dedication, there's a recurring frustration.

Almost every agency I encounter struggles with the inadequate combination of CMS, optimization tools and third party data. Particularly for mid-sized projects, the available tools are often too complex and expensive ("server-side" tools), or they lack the necessary performance and have issues with third-party data ("client-side" tools).

I often observe this mismatch leading to suboptimal solutions, which hinders the delivery of impactful digital experiences despite the hard work put in to achieve them.

The way I see it, when combining a headless CMS with optimization tools, you only have two main options: server-side and client-side optimization. In the following sections, I will explain more about what these are and discuss the pros and cons of each approach in more detail.

Server-side tools: Ideal for large projects

Let’s start with the Server-side optimization tools, these tools are software solutions that conduct experiments from the server. This method guarantees fast and secure content delivery on your website, resulting in a seamless user experience. When it comes to delivering high performance and robust security, server-side optimization tools integrated with a headless CMS are a top choice.

However, server-side solutions are not without their drawbacks. They are often complex and expensive, requiring significant resources to implement and maintain. This makes them ideal for large projects with the budget and technical expertise to manage such systems.

For medium-sized projects, though, the complexity and cost can be difficult. These projects may not have the resources to invest in a server-side solution, making it less suitable despite their performance benefits. They also struggle with the high burden of management and maintenance.

Client-side tools: User-friendly but flawed

On the other side we have client-side optimization tools, these tools are software solutions that process and optimize content delivery on the user’s browser rather than on the server. Popular client-side optimization tools include VWO and Optimizely, which offer features for A/B testing, personalization, and other enhancements directly within the user’s browser.

Client-side tools are often favored for their simplicity and ease of implementation. When combined with a headless CMS, they allow for quick experiments, making them an attractive option for many agencies.

Client-side tools, while user-friendly, have significant trade-offs. They rely on the end user's browser for processing optimizations, which can lead to performance issues, slower load times, and a less smooth user experience. Additionally, these tools rely on third-party cookies, classifying them as third-party data. As privacy regulations become stricter and major browsers cease to allow third-party cookies, marketers are being forced to explore new strategies to remain successful.

Security is another concern. Client-side solutions are more vulnerable to attacks since the data processing occurs on the user’s device rather than on a secure server.

Additionally, these tools are prone to the flicker effect, where content momentarily displays incorrectly before the optimizations are applied, which can disrupt the user experience.

Finally, modern web architectures like React, Angular, and Vue.js generate dynamic class names with each redeployment, which can cause client-side visual editors to break. This fundamental incompatibility has resulted in decreased reliability of client-side tools.

Far from ideal for medium-sized projects

Agencies often find themselves in a difficult position when choosing the right CMS and optimization tools for medium-sized projects. They have unique needs that are not fully addressed by either server-side or client-side solutions.

Server-side solutions offer excellent performance and security but are too complex and expensive. These solutions require significant resources and technical expertise, which can be out of reach for many projects.

On the other hand, client-side solutions are more affordable and easier to implement. However, they come with their own set of problems. Performance issues, security vulnerabilities, and the flicker effect can significantly impact the user experience, making these tools less effective for conversion optimization.

This leaves agencies with limited options. I often see agencies either completely avoid optimization or use tools that don't adequately meet their needs. This gap in the market highlights the need for a solution that combines the best features of both server-side and client-side tools.

Introducing the conversion-centric headless CMS

Here is where the solution comes in: A conversion-centric headless CMS is an innovative solution that not only manages and publishes content like any other headless CMS but also includes built-in features for optimization.

These features, such as A/B testing and personalization, are built directly into the CMS, allowing you to tailor content to individual user preferences and test different variations to find the most effective strategies.

A conversion-centric CMS combines the best aspects of server-side and client-side optimization tools. It offers high performance and security without the complexity and cost of server-side solutions, while avoiding the performance issues and vulnerabilities of client-side tools.

One key advantage is the seamless integration of advanced features like personalization and A/B testing. By processing optimizations server-side, it eliminates performance bottlenecks and security risks, resulting in a smoother, more secure user experience without the flicker effect.

This solution is also user-friendly and quick to implement, requiring minimal technical expertise and budget.

While it may not offer all niche features of specialized tools, a conversion-centric headless CMS focuses on the essential features that drive most engagement and conversions.

By bridging the gap between expensive server-side solutions and accessible but flawed client-side tools, I think that a conversion-centric headless CMS is perfect for medium-sized projects. It brings top-market functionality to every business, giving them the control to compete effectively and deliver exceptional customer experiences.

Let me tell you about the website, where they faced the challenge of increasing engagement among tourists. Their goal is to make tourists explore beyond the typical attractions. To achieve this, they turned to Prepr’s conversion-centric headless CMS, implementing personalized content.

By leveraging Prepr CMS, collected data on visitor interests through the website. This data was used to create segments based on interests, such as shopping or museums. The website then displayed personalized recommendations, matching visitors to relevant segments and content. This approach ensured visitors discovered attractions that aligned with their interests, spreading out tourist traffic and reducing overcrowding at popular sites.

The personalized content led to significant improvements. Visitors engaged more with tailored recommendations, enhancing their overall experience and interaction with the website. Engagement increased by 10%, and the click-through rate (CTR) to partner pages tripled.

The case study showcases the effectiveness of a conversion-centric headless CMS in bringing top-market functionality to all companies.


Digital Agencies are continuously facing an ongoing challenge of balancing performance, security and ease of use, all while staying within budget. Simultaneously, there is a significant realization that delivering top-notch customer experiences is more important than ever and traditional solutions, whether server-side or client-side, often fall short for medium-sized projects, leaving a significant gap in the market.

A conversion-centric headless CMS steps in to bridge this gap, combining the best features of both server-side and client-side optimization tools. It integrates advanced functionalities like personalization and A/B testing directly into the CMS, offering high performance and excellent security without the complexity and high costs associated with traditional server-side solutions. At the same time, it avoids the performance issues and security risks typical of client-side tools.

This solution is particularly well-suited for medium-sized projects, bringing functionality that was once only accessible to large companies into the hands of every business.

I hope this information proves valuable to digital agencies seeking to make informed decisions. This tangible solution is ideal for agencies working on medium-sized projects. If you're ready to explore this solution, contact us to learn more or schedule a demo. Discover how a conversion-centric headless CMS can significantly enhance your content management and optimization approach. Together, we can create outstanding customer experiences that efficiently boost engagement and conversions within budget.