AI/ML Engineer

Team Charter:  

The Data team is the engine of intelligence at OfferUp. Our mission is to transform massive amounts of marketplace data into seamless, safe, and personalized experiences that empower millions of people to connect and prosper. We bridge the gap between complex algorithms and real-world customer impact across search, trust & safety, and personalization.

About the role: 

AI is transforming how millions of people buy, sell, and connect on OfferUp - and this role is at the center of making that happen. As an AI Engineer on the Data team, you will own the production systems — from agentic workflows and RAG pipelines to LLM integrations - that turn our marketplace intelligence into real customer experiences. From enhancing search ranking and personalization to powering fraud detection and generative AI features, your work will have a company-wide impact and be felt by millions of users every day. The Data team reports into the broader engineering organization and directly influences OfferUp's most critical product surfaces.

We are looking for an AI Engineer to join our Data team. This team is tasked with building the core intelligence - supporting  search ranking, recommendation engines, fraud detection, and generative AI features - that is critical to OfferUp's success as the leading local marketplace. You will be part of a cross-functional team that includes Data Engineering and Data Science, serving as the bridge that turns research and models into shipped, production-grade AI systems.

What we love about this role: 

• Breadth of Impact: You won't be siloed; you will build AI systems that drive results across Search & Discovery, Trust & Safety, Advertising, and core Personalization.
• Modern AI Stack: Work with agentic frameworks (LangChain, LangGraph), RAG architectures, and LLM APIs to solve real marketplace problems.
• Production Ownership: You will build, ship, and own AI features end-to-end, from design through deployment.
• Collaborative Environment: Work alongside Senior Data Scientists and Engineers, positioning you at the intersection of research and production.

In this role, you will 

• Design and build agentic AI systems and RAG pipelines for production features across the marketplace.
• Integrate LLMs into product experiences across search, categorization, communication, and trust & safety.
• Partner with Data Scientists and Engineers to turn research into shipped products.

Here’s more of what you will get to do:

• Impact on Product: Deliver the next generation of Search, Personalization, and Trust & Safety features powered by reliable, production-quality AI systems.
• Impact on Company: Directly contribute to key business KPIs (conversion, retention, fraud reduction) by turning data science insights into shipped capabilities.
• Critical Projects: Production RAG pipelines for intelligent discovery; agentic workflows for marketplace automation; tooling and infrastructure for rapid, safe LLM deployment.

You’ll thrive in this role if you have:.

• 2-4 years building and deploying AI/ML systems in production.
• 2+ years professional Python development.
• Hands-on experience with agentic frameworks (LangChain, LangGraph, or similar) including function calling and tool-use design.
• Practical experience building RAG systems (vector search, semantic chunking, rerankers).
• Experience with LLM APIs, prompt engineering, and structured outputs.
• Proficiency with async Python (asyncio, streaming) and Pydantic.
• Strong SQL skills for large-scale data systems.
• Bachelor's in CS, Math, Statistics, or related field (or equivalent experience).
• Collaborative mindset and strong communication skills.

Helpful, but not required: [nice to haves]

• LLMOps tooling: evals (Ragas, DeepEval), observability (LangSmith, Arize Phoenix), guardrails (NeMo).
• Cloud deployment of AI services (AWS preferred).
• GraphRAG or knowledge graph integration (Neo4j/FalkorDB).
• ReAct, Plan-and-Solve, or multi-agent collaboration patterns.

Compensation Range: $140,000 - $160,000

OfferUp offers a comprehensive compensation and benefits package where you’ll be rewarded based on your performance and recognized for the value you bring to the business. Individual salaries within our ranges are determined through a variety of factors, including but not limited to education, experience, knowledge, skills, and geography. All roles will receive equity in OfferUp as part of their compensation, the amount of equity varying depending on the individual’s level and experience.

Benefits (all US roles): In addition to our compensation package, this role is eligible to enroll in health insurance, healthcare savings and spending accounts, retirement savings benefits (401(k) plan with match), basic and voluntary life insurance, disability benefits, and paid time off for sick leave, family and/or medical leave, vacation, and 12 company holidays. In regard to vacation time, OfferUp has a flexible vacation policy, and, in general, full-time, exempt employees will be expected to take 3-5 weeks (15-30 days) of pre-planned vacation time per year. Vacation needs are flexible and will naturally vary from year to year based on individual circumstances and business needs. In regard to sick time, all full-time employees (exempt and non-exempt) will be granted 12 days (96 hours) of sick time per year (pro-rated if the start date is other than January 1). Your recruiter can share more details about specific benefits during the interview process.