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

About Redcare Pharmacy:As Europe’s No.1 e-pharmacy, Redcare Pharmacy is powered by passionate teams and cutting-edge innovation. We strive to create a healthy, collaborative work environment where every employee feels valued and inspired to contribute to our vision “Until every human has their health”. If you’re seeking a career that offers purpose and aligns with your values, join us and begin your #Redcareer today.About the role: As Senior Backend Engineer, AdTech (m/f/d), you will be shaping and evolving our AdTech platform and operating backend services that power advertising products across sponsored search, sponsored products, campaign management, ad serving, targeting, reporting, and measurement with a strong focus on scalable architecture, engineering best practices, and performance optimization. You will serve as the technical leader across cross-functional teams and ensure the successful delivery of high-performance advertising solutions. You will collaborate closely with theProduct Managers, Retail Media business team and other stakeholders to turn complex business challenges into robust technical solutions that enable our Retail Media ecosystem to grow and scale.About our tech stack: Node.js, TypeScript, Koa.js (primary) + NestJS, MongoDB (incl. aggregation pipelines), Redis, BullMQ, RabbitMQ, Algolia, Docker, Kubernetes (GKE), CI/CD (CircleCI + ArgoCD), Google Cloud. Integrations with ad-serving platforms. React/Next.js on the frontend.Job DescriptionAbout your tasks:Design, develop, and maintain scalable backend services and APIs supporting retail media products. Build and operate distributed systems that process large volumes of advertising, campaign, auction, and analytics data. Develop low-latency, highly available services for ad serving, targeting, bidding, and campaign execution. Optimize real-time and high-throughput data systems, integrating with MongoDB, Redis, and Algolia to support fast ad delivery and campaign insights. Work with BullMQ and RabbitMQ for reliable message queueing across distributed services. Ensure software quality through automated tests (TDD/BDD preferred). Design and implement distributed caching strategies, cache invalidation mechanisms, and performance optimizations. Ensure systems meet reliability, performance, scalability, and security requirements. QualificationsAbout you:You have experience building products in Retail Media, AdTech, MarTech, E-commerce, Search, or Recommendation systems. You demonstrate seniority through ownership, technical excellence, proactive problem-solving, and the ability to independently drive initiatives from concept to production. You have hands-on experience building Ad Serving Platforms, Campaign Management Systems, Search Advertising Solutions, Auction or Bidding Systems, Attribution and Reporting Platforms. You posses strong software engineering principles Object-Oriented Design, SOLID Principles, Design Patterns, Testing Strategies, API Design. You have experience building and operating cloud-native applications on AWS, GCP, or Azure. You have practical experience with Infrastructure as Code (IaC), CI/CD pipelines, and automated deployment practices. You are well-versed in security best practices, including authentication and authorization (OAuth2, JWT), encryption, secrets management, and secure software development practices. You understand the importance of observability and have experience working with monitoring, logging, tracing, and alerting solutions. You bring a strong DevOps mindset and take ownership of software throughout its lifecycle, from development and deployment to operation and continuous improvement.