Personalization and Ad Serving Platform for Klarna

1. Ensure optimal performance when experiencing high volumes of traffic

We were presented with a huge scope that in some areas contained a lot of requirements, while others contained a few. With this scope, we had to provide time and cost estimates, create an initial product roadmap, and list project milestones.

2. Deliver a Personalized User Experience and Consistent Messaging

Klarna On-site Messaging allows merchants to deliver the best user experience possible by personalizing the messages shown to visitors, such as greeting them by first first name, showing them products they might like based on their interests, displaying delivery options based on their location, and presenting them with payment options based on their preferences.

The messages also need to be consistent throughout their time on the website, meaning we couldn’t show them one payment option on the first page and then a different one on the next page.

We also had to make sure that we uphold user trust between Klarna, the merchants, and consumers by respecting various user privacy rules and features, such as the EU’s General Data Protection Regulation (GDPR).

3. Ensure the interstitials (pop-up messages) are compatible with all merchant websites

As part of Klarna’s goal to deliver a consistent and seamless user experience, we had to make sure the interstitials (the actual pop-up messages shown to visitors) are shown in the same way across all merchant websites.

To achieve this, we had to ensure the interstitials were compatible with all browsers and device types, as well as with merchant websites.

Below are the solutions to the challenges listed above:

Deployed a number of Amazon Web Services

We chose to host the Klarna On-site Messaging on Amazon Web Services (AWS) as it offered the best solution for this challenge. Also, we have a lot of experience working with AWS and knowledge of the various services.

Specifically, we utilized various caching methods (browser, DB caches, etc.), configured and made optimizations to the infrastructure, deployed Auto Scaling groups, introduced stress tests to test the performance of the Klarna On-Site Messaging platform before each deployment, and made the staging environment similar to the production environment.

Changed the ad server’s behavior

We cached the responses from the ad server for each session and changed the behavior of the ad server to check whether the parameters for a given placement had changed (e.g. the price of a product listed on a merchant’s site).

Used iframes and a JSON Remote Procedure Call setup

The frontend part of the application provides clients with a unique user experience that has not yet been seen in advertising technology solutions. It was built using JavaScript with Knockout JS as the framework to ensure complete usability. The UX&UI design elements emit a recognizable brand image and deliver a simplistic user experience to what is otherwise a highly complex technology.

• Support and strong cooperation with Klarna.
• Experienced developers with knowledge about the inner-workings of online advertising technology (AdTech).
• Our experience in designing, building, and maintaining AdTech and MarTech platforms.
• Our full-service development teams.
• Our agile and incremental approach to AdTech & MarTech development, including story mapping and the MVP Scoping phase (e.g. choosing the tech stack and basic architecture).

Klarna’s partnership with us produced the following results:.

• The Klarna On-Site Messaging platform handles 100M+ user profiles, can render personalized messages within 50 milliseconds, and handle peak loads well above 20,000 queries per second (QPS).
• Visitors are shown a personalized experience and consistent messaging during their time on merchant sites, provided they’ve consented to this type of personalization.
• The network traffic is lower as we don’t make unnecessary calls to the ad server.
• Interstitials are consistent across all the merchant websites and displayed in the same way everywhere.