Senior Recommendation Systems Engineer (Wonderscent)

Wonderscent is an early-stage, AI-first startup changing how people discover and choose fragrances.

We're building a product that helps people find scents based on their preferences, emotions and the experiences they're looking for.

Our founders are second-time entrepreneurs with a successful exit and experience at Pinterest. We're a small team building a product where search, recommendations and personalization are at the core of the user experience.

We're looking for a Recommendation Systems Engineer to take ownership of how Wonderscent understands user preferences and recommends fragrances.

You'll work directly with the founders, engineers and product team to design, build and improve recommendation systems from the ground up.

What you'll work on

• 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.
• Use AI coding agents such as Claude Code and Codex as a core part of the development workflow.

What we're looking for

• 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.

We care more about what you've built and the impact you've made than a particular tech stack or job title.

What makes this role different

• Real ownership. You'll help define the recommendation architecture and decide what to build, not just implement predefined tasks.
• Experienced founders. Work directly with second-time founders who have already built and exited a company.
• Small team, direct impact. Your decisions will directly influence the product and how users experience it.
• AI-first development. AI coding agents are part of how we build software, not an occasional productivity tool.
• Equity. Share in the long-term success of the company.
• Flexibility. Remote work, with Warsaw preferred and an office available for local teammates.

If you enjoy building intelligent systems, solving ambiguous problems and owning the results of your work, we'd love to hear from you.