Senior Recommendation Systems Engineer

• Design and build personalized recommendation systems, semantic search and similar-fragrance discovery
• Develop candidate retrieval, ranking and re-ranking approaches
• Solve cold-start challenges and identify useful user signals
• Build data pipelines and ML-powered services that support recommendations
• Define evaluation metrics, run experiments and measure recommendation quality
• Make practical architecture decisions and take systems from idea to production
• Contribute to backend and product engineering when needed
• Work directly with the founders, engineers and product team
• Help define the recommendation architecture and decide what to build
• Use AI coding agents such as Claude Code and Codex as a core part of the development workflow

• Hands-on experience building or improving recommendation systems, search ranking or personalization in production
• Strong understanding of retrieval, ranking, ML models and experimentation
• Ability to design and own systems end-to-end, not just individual models
• Solid software engineering and backend development skills
• Experience working with user behavior data and measuring product impact
• Product mindset and ability to make independent technical decisions
• Comfort working in a small team with evolving priorities
• Interest in AI-first engineering and using coding agents in daily development
• Experience in e-commerce, marketplaces, consumer products or discovery platforms is a plus
• Willingness or ability to use AI coding agents such as Claude Code and Codex in daily development

• Equity / share in the long-term success of the company
• Remote work flexibility
• Office available for local teammates in Warsaw