OfferUp is seeking a Senior Data Scientist to play a pivotal role in shaping the company’s marketplace intelligence by leading the research, design, and implementation of machine learning solutions. This position directly impacts customer experience and key business KPIs such as conversion, retention, and safety, with a focus on long-term value creation.
What You'll Do
- 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 using 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 the BigQuery data warehouse.
- Optimize search ranking algorithms using modern learning-to-rank techniques.
- Develop a robust framework for assessing and deploying LLM-based agents.
- Refine 'Crime Risk' and user reputation models to maintain a safe marketplace.
What We're Looking For
- 5+ years of building and shipping ML models and data solutions with quality.
- 4+ years of professional software development in Python.
- Strong proficiency in querying and retrieving data using SQL from large-scale distributed systems.
- Ph.D. or Master’s Degree in Computer Science, Mathematics, Statistics, or a related technical field OR Bachelor’s degree and relevant work experience.
- Deep understanding in a classical NLP method (e.g. n-grams, NER, POS tagging) and ML tasks (e.g. semantic analysis, text classification).
- Proficiency in deep learning frameworks such as PyTorch, TensorFlow or Keras.
- Experience training models in cloud environments (Databricks/Sagemaker preferred).
- Proven track record of mentoring junior or mid-level team members and performing high-quality code and design reviews.
- Collaborative mindset with experience contributing to project roadmaps and technical documentation.
- Impact-oriented: Experience delivering end-to-end projects that solve complex business problems.
- Strong communication skills, with the ability to explain technical concepts to non-technical stakeholders.
Nice to Have
- Practical experience with LLMs, deep models (RNN, LSTM) and their applications is highly preferred.
- Experience deploying models as microservices within cloud infrastructure (AWS preferred).
- Hands-on experience with Spark for large-scale data processing.
- Working knowledge of deep learning methods applied to images (CNNs, ResNet).
Technical Stack
- DataBricks, SageMaker, BigQuery, Python, SQL, PyTorch, TensorFlow, Keras, Spark, AWS, LLMs, RNN, LSTM, CNN, ResNet
Team & Environment
- Data team focused on marketplace intelligence across search, trust & safety, personalization, and advertising
Benefits & Compensation
- Health insurance
- Healthcare savings and spending accounts
- Retirement savings benefits (401(k) plan with match)
- Basic and voluntary life insurance
- Disability benefits
- Paid time off for sick leave, family and/or medical leave, vacation, and 12 company holidays
- Flexible vacation policy: full-time, exempt employees expected to take 3-5 weeks (15-30 days) of pre-planned vacation per year
- 12 days (96 hours) of sick time per year for full-time employees (pro-rated if start date is not January 1)
Compensation includes a salary range of $190,000 - $220,000. All roles receive equity in OfferUp, with amounts varying based on level and experience. Final compensation is determined by education, experience, knowledge, skills, and geography.
Work Mode
- Hybrid role based in Bellevue, WA or remote in Florida
OfferUp provides equal employment opportunities (EEO) to all employees and applicants for employment without regard to race, color, religion, sex, national origin, age, disability, or genetics. The company complies with applicable state and local laws governing nondiscrimination in employment and prohibits workplace harassment based on protected characteristics.
