Senior Backend Engineer - Search and Discovery

Company Description ABOUT YOU is one of Europe’s fastest growing e-commerce companies. Based in Hamburg and Berlin, we operate at the intersection of fashion and technology. Our mission is to rethink online shopping and make it personal and seamless. This takes more than good ideas. It takes people who take initiative and challenge the status quo. We believe in flat hierarchies, direct communication, and pragmatic decisions. No long approval chains. Just ownership, trust, and clear responsibility. We work hard, but we also believe in enjoying the ride together - over team lunches, afterwork drinks, company events, or a quick coffee in between meetings. If this sounds like you, ABOUT YOU could be the right place to bring in your perspective. Job Description Develop the search engine behind ABOUT YOU, covering query understanding, entity resolution, and semantic vector search in Node.js/TypeScriptBlend OpenSearch relevance, embedding similarity, and behavioral re-ranking signals into unified search resultsBuild search-index pipelines (entities, synonyms, k-NN product vectors) streaming data from BigQuery into OpenSearchIntegrate LLMs and embedding models (Gemini, Vertex AI) under tight latency budgets with caching and fallback layersGuard search relevance using golden lists, regression suites, and continuous A/B experimentsShape architecture alongside our Tech Lead and collaborate closely with data analysts, engineers, and product managers Qualifications You love investigating the "why" behind search outcomes and turning those findings into actionable technical improvements5+ years of experience building scalable, low-latency backend APIs (Node.js/TypeScript preferred, or fast-converting from Java, Go, or Kotlin)Real depth in Elasticsearch/OpenSearch (mappings, custom analyzers, percolators, scoring functions) beyond just basic query clientsStrong algorithmic intuition for ranked data (merging, deduplication, score blending, and latency trade-offs)You're excited to bridge backend engineering and ML by serving model scores, embeddings, or LLM features in productionFluent English communication skills and a pragmatic, data-curious mindset Nice to Have IR/NLP fundamentals (tokenization, multilingual search, relevance evaluation frameworks)Vector search experience (k-NN/HNSW indices, SigLIP embeddings, recall vs. latency tuning)LLM engineering (prompt caching, timeout budgets, Datadog LLM Observability)Familiarity with BigQuery, dbt, or Dagster pipelines Additional Information Your perks at a glance: Visit our benefits page. Simply apply online via our career page - we will get back to you as soon as possible! A Place Where You Can Be You We take it as our responsibility to create an environment where everyone feels welcome, exactly as they are. Different backgrounds and perspectives make us stronger and shape our culture in ways that matter. What we stand for internally, we stand for as a brand: acceptance, inclusion, and a fairer approach to fashion.