Senior Backend Engineer - Ranking Systems (all genders)
About You SE & Co. KG4 days ago
Hamburg, Germany or Berlin, GermanySenior
Responsibilities
- Build and own the high-throughput Spotsetter ranking engine.
- Blend machine-learning model outputs with business logic such as campaign boosts and sponsored items.
- Design batch write pipelines that stream data from BigQuery into Postgres and MySQL.
- Develop low-latency serving APIs using Fastify and Node.js/TypeScript.
- Apply ranking, deduplication, latency, and constraint logic to product sorting.
- Collaborate with data engineers, product managers, and commercial teams on data-driven ranking decisions.
- Maintain a clean codebase and contribute architectural ideas in collaboration with the Tech Lead.
Requirements
- At least five years of experience building backend systems.
- Strong hands-on SQL knowledge, including Postgres/MySQL schema design, query optimization, and batch operations beyond basic ORMs.
- Good algorithmic intuition for sorted data, deduplication, latency trade-offs, and constraint logic.
- Interest in serving machine-learning scores or ranking data in live backend systems.
- Node.js and TypeScript experience preferred, with Java, Go, or Kotlin backgrounds also welcomed.
- Clear communication skills in English and a pragmatic, solution-oriented mindset.
- Experience with BullMQ, Redis, or batch-processing pipelines is a plus.
- Exposure to AWS Step Functions, CDK, GCP, or BigQuery is a plus.
- Background in e-commerce, sponsored products, or ad-tech systems is a plus.
- Curiosity about learning-to-rank algorithms is a plus.
Benefits
- Inclusive and welcoming workplace culture focused on acceptance and inclusion.
- Team lunches, afterwork drinks, company events, and informal coffee breaks.
- Role based in the company’s Hamburg and Berlin locations; application is online through the career page.
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.