Performance optimization in Salesforce Marketing Cloud: When complexity delays delivery

However, these performance issues are not typically caused by misconfigurations in the traditional sense. Rather, they are caused by the intensive use of complex data structures and logic. Utilizing the full capabilities of Data Extensions and dynamic content puts a strain on the query and rendering capacities of SFMC’s application servers at the time of delivery.

The impact of dynamic templates on performance in Salesforce

With Salesforce Marketing Cloud, you can create highly personalized email templates. You can dynamically assemble elements such as logos, images, product recommendations, and footer information based on brand guidelines, region, or individual purchasing behavior. This automation significantly increases operational efficiency because a single master template can generate many variations.
The technical challenge is that these dynamic templates are rendered only at the exact moment of sending and for each recipient individually by default. This means any programming logic contained within, such as AMPScript or GTL, is only executed when the email is about to leave the platform. For each recipient, the system must perform database queries (lookups) against various data extensions to identify and compile the relevant content blocks into a final HTML document. With high send volumes, this "just-in-time" personalization creates a significant computational load on the application servers, causing them to become a bottleneck.

According to Salesforce Support, loading an external content block alone can take up to 2.4 seconds. Complex personalization, such as numerous parallel lookups to data extensions during delivery, can reduce throughput by up to 25 percent. Using templates with hundreds of referenced variables creates an enormous load precisely when the system must deliver peak performance.

The operational consequences are:

• Significant delays in the sending process (up to several days for mailings involving millions of recipients)
• Users experience a degraded user interface (e.g. slow navigation)
• Delayed test emails hinder workflows and make it difficult to ensure the quality of subsequent campaigns.

Performance optimisation strategies:

The options for improving performance vary greatly depending on the SFMC instance and its data structures. In our experience, two approaches have proven particularly effective. The best results are achieved through precalculation and HTML minification, both of which are tailored to the specific setup.

• Precalculation: A script consolidates the referenced external content blocks into a single email template in advance. This means that elements that are identical for larger recipient groups (e.g. footers, logos or CSS definitions) are already prepared at the time of sending. During delivery, Salesforce Marketing Cloud simply needs to insert the individual personalizations (such as profile information or personal recommendations).
• HTML minification: During this process, elements that only serve human readability, such as indentation spaces or CSS elements added by the Content Builder to enable the SFMC editor to process complex layout modules, are removed. These elements serve no function whatsoever in displaying the email to the recipient. Depending on the campaign, this can reduce the file size of each email by approximately 10–20 kB (20–35%). For large emails and distribution lists, reducing the file size by 10 to 20 kilobytes per email significantly reduces the load on the system.
  A relevant side effect of minification is that many emails can therefore remain below Gmail’s 102-kilobyte limit. This prevents 'Gmail clipping', where content at the end of the message is cut off.

Precalculation and minification occur as the final step before sending. This enables the marketing team to continue using the familiar, easy-to-read templates in Salesforce Marketing Cloud Content Builder, and operational work is unaffected by the technical clean-up.

Using Salesforce's native optimization features

Salesforce offers its own solutions to performance issues in the form of 'pre-built burst sending' and precalculation. However, depending on the specific use case, factors such as high additional costs, limitations in compatibility with Journey Builder, or incomplete documentation mean that Salesforce's native features may not be the best choice. Therefore, selecting the optimal method requires detailed analysis on a case-by-case basis.

Conclusion: Optimizing the performance of Salesforce Marketing Cloud is multifaceted

While highly dynamic templates are a common cause of performance issues, they are not the only reason. Other relevant factors include:

• Inefficient SQL queries without optimized index structures
• Resource conflicts caused by competing SQL activities when multiple SQL queries run in parallel across different automations and simultaneously access identical data extensions
• Poor data hygiene (e.g., bloated databases without deletion routines)
• Suboptimal data sourcing leading to duplicates or unnecessary multiple mailings

To identify the specific bottlenecks of a Salesforce Marketing Cloud engagement instance, a structured analysis is recommended.

As part of our Marketing Cloud Health Check, we examine the existing setup, evaluate existing processes, and develop a prioritized list of actions to ensure your SFMC instance is optimized for efficiency and high performance. Learn more about Publicare’s Marketing Cloud Health Check.

Do you have questions about the performance of your Salesforce Marketing Cloud account? Our certified experts are happy to assist you with analysis and optimization.‍