Senior Backend Engineer, AdTech (m/f/d)

About Redcare Pharmacy

Redcare Pharmacy is positioned as Europe’s leading online pharmacy. The company emphasizes innovation, teamwork, and a supportive workplace where people are encouraged to contribute to the mission of improving access to health for everyone. This role is suited for someone looking for meaningful work in a values-driven environment.

Role Overview

As a Senior Backend Engineer focused on AdTech, you will help evolve the advertising technology platform and the backend services behind retail media products. Your work will support sponsored search, sponsored products, campaign administration, ad delivery, targeting, reporting, and measurement. The role has a strong emphasis on scalable system design, high performance, and engineering quality. You will also act as a technical lead across cross-functional teams and partner with product managers, the retail media business team, and other stakeholders to turn complex business needs into reliable technical solutions that support the growth of the retail media ecosystem.

Technology Environment

The backend stack includes Node.js, TypeScript, Koa.js as the main framework, with NestJS also in use. The systems work with MongoDB, including aggregation pipelines, Redis, BullMQ, RabbitMQ, and Algolia. The infrastructure uses Docker, Kubernetes on GKE, CI/CD via CircleCI and ArgoCD, and Google Cloud. The platform also integrates with ad-serving systems, while the frontend uses React and Next.js.

Key Responsibilities

• Architect, build, and support backend services and APIs for retail media products.
• Create and run distributed systems that handle large-scale advertising, campaign, auction, and analytics workloads.
• Develop services for ad serving, targeting, bidding, and campaign execution with low latency and high availability.
• Improve real-time and high-throughput data flows by working with MongoDB, Redis, and Algolia to enable quick ad delivery and actionable campaign insights.
• Use BullMQ and RabbitMQ to manage dependable messaging across distributed components.
• Raise software quality through automated testing, with TDD and BDD approaches preferred.
• Build caching approaches, cache refresh/invalidation logic, and other performance enhancements for distributed systems.
• Maintain reliability, scalability, security, and performance across the platform.

Candidate Profile

The ideal candidate has experience in Retail Media, AdTech, MarTech, E-commerce, Search, or recommendation-driven products. Seniority is shown through strong ownership, technical depth, proactive problem-solving, and the ability to take ideas from concept to production independently. Hands-on experience with ad serving platforms, campaign management systems, search advertising, bidding or auction systems, and attribution/reporting solutions is highly relevant.

You should have a solid command of software engineering fundamentals, including object-oriented design, SOLID principles, design patterns, testing strategies, and API design. Experience building and operating cloud-native applications on AWS, GCP, or Azure is expected, along with practical exposure to infrastructure as code, CI/CD pipelines, and automated deployments.

A strong understanding of security practices is important, including authentication and authorization using OAuth2 and JWT, encryption, secrets handling, and secure development methods. You should also be comfortable with observability tools such as monitoring, logging, tracing, and alerting, and bring a DevOps-oriented mindset that covers software from development through deployment and ongoing operation.

Additional Information

The position is a full-time onsite role in Berlin, Germany.