Advanced Email Marketing – Legally Compliant and Customer-Centric

Project at a Glance

• Selection and integration of a new email service provider
• Legally compliant implementation of all processes in international email marketing
• Strengthening of email marketing reputation, including continuous fraud detection
• Complete replacement of the legacy system and integration of new markets
• Development of a new AWS-based, cloud-native microservices architecture
• Data migration, including data cleansing and quality assurance

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Initial Situation

Breuninger faced the challenge of phasing out a legacy email marketing system that relied on outdated interface technologies with its email service provider and partially distributed data storage. The goal was to make existing email marketing campaigns more efficient while meeting the highest standards of data protection and legal compliance, such as those introduced by GDPR.

Before the project began, the situation was marked by complicated interfaces between numerous internal systems and an inflexible external system, making process changes difficult and slowing down efficient data exchange. Some business processes were running in a non-transparent manner within the external system. As a result, Breuninger could not realistically implement its strategy to expand into new markets for international email campaigns.

The new system also needed to provide more comprehensive analytics capabilities to enable continuous optimization, safeguard email reputation in the long term, and expand it further. Data inconsistencies in the legacy system were to be eliminated during the migration. Seamless integration with existing systems as well as ensuring legal compliance of all marketing communication were key requirements.

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Solution

pentacor supported Breuninger in modernizing its email marketing and positioning it for the future. This began with professional and technical guidance in selecting a new email service provider, including evaluation of business processes and extensive technical integration testing.

The complete technical implementation of business processes was redesigned and realized within a dedicated Kubernetes cluster, enabling end-to-end process accountability. Special attention was given to ensuring legally compliant processes (e.g., unsubscribe deadlines), even in externally integrated systems such as survey providers.

The existing distributed backend system was fully replaced, and the frontend – taken over by another team – was streamlined to essential functions and enhanced with innovative fraud detection mechanisms.

As part of the migration, data inconsistencies were resolved and mechanisms introduced to increase the efficiency of email marketing, such as personalized customer communication based on individual preferences.
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Technology and Architecture

The newly developed solution is based on a scalable and extensible cloud-native microservices architecture, built within a dedicated AWS Cloud Domain. The entire infrastructure setup was created using Infrastructure-as-Code and included the Kubernetes cluster, network setup (ingress, egress, security), databases (PostgreSQL), messaging systems (Kafka), and a data mesh connection (Google BigQuery). The microservices were implemented in Java and Spring Boot.

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Result

With the successful completion of the project, Breuninger now has a modern, flexible, and future-proof system for promotional email communication. The system seamlessly integrates the new email service provider and transparently maps processes around sign-ups, unsubscribes, and the delivery of marketing emails. As a result, Breuninger was able to significantly improve its reputation in email marketing.

Seven new markets (countries) were successfully integrated and consolidated with the data from existing markets. During migration, datasets were transferred as a unified data set after careful plausibility checks and data cleansing. This significantly improved operational efficiency and scalability while laying the technological foundation for sustainable growth.

Legal compliance was ensured through various technical mechanisms, such as failover protection, event-driven near real-time processing, and monitoring.

During the project, new requirements in fraud detection emerged. Thanks to the forward-looking, extensible service architecture, defensive mechanisms such as address validation and normalization could be implemented quickly and effectively.