OfferUp

Frontend Engineer

• Lead the research, design, and implementation of end-to-end machine learning solutions, from initial hypothesis and data exploration to A/B testing and production deployment.
• Own the evaluation and "prompt engineering" strategy for Large Language Models (LLMs) to enhance product features like automated categorization and user communication.
• Act as a strategic partner to Product and Engineering leaders, translating business goals into data science roadmaps that prioritize long-term customer experience over short-term gains.
• Drive the next generation of Search and Personalization features; use LLMs to create "magic moments" for users while ensuring model outputs are safe, accurate, and valuable.
• Directly influence key business KPIs (e.g., conversion, retention, fraud reduction) by identifying untapped opportunities within our BigQuery data warehouse.
• Optimize our search ranking algorithms using modern learning-to-rank techniques; develop a robust framework for assessing and deploying LLM-based agents; refine our "Crime Risk" and user reputation models to maintain a safe marketplace.

Senior Data Scientist – Hybrid, Bellevue, WA, Florida

• Develop a technical strategy for our team
• Develop highly scalable real-time microservices without compromising on reliability, latency, and monitoring.
• Work collaboratively with cross-functional teams to design and implement new features
• Collaborate with OfferUp wide engineering teams to surface common pain points, develop solutions and evangelize best practices
• Identify when to replace and when to rebuild legacy systems
• Support, mentor, and help other engineers in the team
• Participate in a reasonable on-call rotation with the rest of the team
• Collaborate with stakeholders to drive features and assess timelines.
• Help maintain code quality in existing applications.
• Create solutions and/or frameworks that make other team members better and faster
• Become an SME for team ownership areas

Senior Data Scientist – Hybrid, Bellevue, WA, Florida

Staff Software Development Engineer