Senior Backend Engineer - Ranking Systems (all genders)
About You SE & Co. KG4 days ago
Hamburg, Germany or Berlin, GermanySenior
Responsibilities
- Develop and take responsibility for the Spotsetter ranking engine.
- Combine machine-learning model results with business logic such as campaign boosts and sponsored products.
- Build reliable batch-write pipelines that transfer data from BigQuery to Postgres and MySQL.
- Develop low-latency APIs for serving ranking data with Fastify and Node.js/TypeScript.
- Collaborate with Data Engineers, Product Managers, and Commercial teams on data-driven product-sorting decisions.
- Contribute to technical architecture, code quality, and the continuous improvement of the backend codebase.
Requirements
- 5+ years of backend-system development experience, ideally with Node.js and TypeScript; experienced developers with Java, Go, or Kotlin backgrounds are also welcome.
- Strong practical SQL skills, including Postgres/MySQL schema design, query optimization, and batch operations beyond basic ORM usage.
- Strong algorithmic understanding of sorted data, deduplication, latency trade-offs, and constraint implementation.
- Interest in connecting backend engineering and machine learning by serving model scores or ranking data in production systems.
- Clear communication in English and a pragmatic, solution-oriented working style.
- Nice-to-have knowledge of BullMQ, Redis, batch-processing pipelines, AWS Step Functions, CDK, GCP, or BigQuery.
- Experience in e-commerce, sponsored products, or ad-tech systems is a plus.
- Interest in learning-to-rank algorithms and willingness to develop expertise in the area.
Benefits
- The company promotes an inclusive, accepting, and fair working environment.
- The company offers flat hierarchies, direct communication, pragmatic decision-making, team lunches, after-work drinks, company events, and informal team gatherings.
- The posting directs applicants to the company's benefits page for additional benefits.
Tech Stack
Categories
About About You SE & Co. KG
ABOUT YOU SE & Co. KG operates an online fashion marketplace for European consumers and licenses commerce technology to brands via its SCAYLE platform. The group sells apparel and lifestyle products through its mobile app and aboutyou.com, and offers a cloud-based enterprise shop system under a license model to retailers. Founded in 2014 and headquartered in Hamburg, it is a publicly listed company.