Collection: App CRO

App Conversion Rate Optimisation (CRO) is about refining an app’s elements and user flow to increase the likelihood that users complete specific actions, like purchases or sign-ups. When it comes to implementing CRO, especially through server-side versus client-side methods, there are several key issues to consider:

1. Speed and Performance

• Server-Side: Typically faster because logic is processed on the server before reaching the user's device. This reduces the impact of network latency and ensures that the app functions more predictably, enhancing the user experience.
• Client-Side: Changes are rendered on the user's device, which can introduce delays. For apps where milliseconds matter, client-side processing can slow down the user experience, especially if the device or network connection is slow.

2. Security and Privacy

• Server-Side: Offers better security as the changes and data are processed on the server, away from the user’s device. This is particularly crucial for apps dealing with sensitive data, like financial transactions or health records.
• Client-Side: Less secure because sensitive data could potentially be exposed in the user’s browser or app memory. Any client-side scripts can also be intercepted or modified, posing additional security risks.

3. Personalisation and User Targeting

• Server-Side: Can offer more advanced personalisation options since it has access to the full backend and can work with data that’s inaccessible to the client side (e.g., user purchase history, advanced segment targeting). This approach also allows real-time A/B testing and targeted experiences based on complex rules.
• Client-Side: Limited to data available within the app and must be explicitly passed. Although it supports personalisation, it’s often less dynamic and sophisticated compared to server-side personalisation.

4. Ease of Implementation and Maintenance

• Server-Side: Often requires more development resources and careful handling of APIs. This can lead to longer implementation times, especially for smaller changes. Once implemented, however, server-side changes are often easier to maintain and scale.
• Client-Side: Generally faster and simpler to implement, especially for front-end tweaks and minor experiments. Non-developers can sometimes manage these changes through tools, making this approach more flexible for quick, iterative CRO tasks.

5. Tracking and Analytics

• Server-Side: Allows for more accurate tracking because actions are recorded directly on the server, reducing the likelihood of discrepancies caused by network interruptions or ad blockers. This results in cleaner data for CRO analysis.
• Client-Side: More prone to data loss and discrepancies, as tracking depends on the user’s device and network. This can be especially problematic in cases where tracking scripts are blocked, reducing the accuracy of conversion metrics.

6. Testing and Experimentation

• Server-Side: Excellent for extensive A/B or multivariate testing without affecting app speed. Users will experience the changes immediately without any flickering, which is common in client-side testing.
• Client-Side: Testing is simpler to implement but can sometimes lead to a "flickering" effect, where users see the original version momentarily before the test version loads. This can disrupt the user experience and impact test reliability.

Choosing the Right Approach

• Use Server-Side if your app demands high security, dynamic content, complex personalisation, or extensive backend involvement. It’s ideal for stable, long-term features and CRO adjustments requiring precise tracking.
• Use Client-Side for faster iterations, small visual tweaks, or when testing concepts. It’s often easier to implement, making it suitable for lighter-weight experiments.

Both approaches can be combined, using server-side for secure, complex changes, and client-side for more superficial or iterative updates. This hybrid approach can offer a flexible balance between security, performance, and experimentation needs in app CRO.