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commercetools is a leading commerce platform company powering the next era of commerce for ambitious enterprises. The company enables AI-driven solutions, bridges digital and physical shopping experiences, and helps industries connect with customers in new ways.
As a Senior Search Backend Engineer on the Discovery Team, you will design and build the retrieval layer behind product discovery for some of the world's most demanding commerce brands. You'll work on a critical evolution in search: shoppers now type full sentences instead of keywords, and increasingly the client calling the API is an AI agent rather than a person.
You will tackle hard problems across every layer—from query understanding down to vector indexes and query cost optimization. Your work will take semantic and hybrid retrieval to general availability, making it fast, affordable, and measurably better across enterprise catalogs.
Key responsibilities:
- Design and implement search functionalities in a PaaS ecommerce Scala backend
- Develop search capabilities combining lexical, semantic, and hybrid retrieval approaches
- Build search-related libraries based on Elasticsearch and MongoDB
- Contribute to search relevance, quality measurement, and metrics
- Run and maintain scalable search infrastructure as code on Kubernetes using Terraform and multi-tenant architecture
- Test software components for usability, functionality, and performance; collaborate with Product Management and DevOps
- Learn Scala and functional programming as primary development tools
- Participate in on-call rotation with a worldwide distributed team for production systems
This is a hybrid role requiring three days per week in the Munich, Berlin, London, or Valencia office.
REQUIREMENTS:
- At least 5 years of experience as a Software Engineer with production experience on the JVM
- Solid understanding of parallel and asynchronous programming, and non-blocking I/O
- Experience developing REST APIs and knowledge of scalable architectures (sharding, replication, load balancing, failover)
- Interest in working with Scala using pragmatic functional programming patterns (support provided if coming from another JVM language)
- Fluent English for work in international teams
- Experience operating multi-tenant SaaS where one tenant's load must never affect another's
- Knowledge of scalable event-driven architectures, including queues and notification topics
- Genuine curiosity for using AI tools to work smarter and more effectively
NICE TO HAVE:
- Hands-on search experience, preferably Elasticsearch or OpenSearch, including understanding of inverted index scoring and ranking
- Practical exposure to vector retrieval (embeddings, approximate nearest neighbor indexes, hybrid ranking)
- Comfort reasoning about relevance with data (precision/recall tradeoffs, ranking metrics, behavioral signals)
- Experience with infrastructure work (Helm, Kubernetes, Rust)
