Senior Machine Learning Engineer

As a Senior Machine Learning Engineer in the Search Quality team, you will improve the e-commerce experience for hundreds of millions of users across the world by building the systems that power relevance for global retailers - from fashion and grocery to electronics and hardware.

Your primary focus will be relevance evaluation and quality improvements:

• LLM-based evaluation. We fine-tune our own models to assess relevance. This involves teaching the model to understand query intent, represent items from messy catalog data, and align model judgments with real user behavior.

• Real-time quality in production. Reranking, filtering, signal computation. Latency is a strict requirement, so quality vs speed tradeoff is constant.

• Automated quality monitoring and agentic insights. Pipelines to detect degradations and find underperforming patterns. Agent-based systems that generate actionable recommendations for the product data and search configurations.

What makes this interesting:

• Multi-domain, multi-language, at scale - 40+ languages, 20+ domains. The models need to generalize across all of them - without per-customer rules or overrides.

• No universal ground truth. A grocery retailer and a fashion retailer may have different perceptions on what "relevant" means.

• Efficiency at scale. Optimizing and scaling LLM inference across our entire customer base.

Requirements:

• 4+ years shipping production ML systems

• Experience with search, information retrieval, or recommendation systems

• Hands-on experience with fine-tuning, evaluation frameworks, and scaling LLM deployments

• Strong Python and PyTorch. Fluency in SQL and data orchestration tools (Spark, Airflow)

• Experience designing and running A/B tests to validate model impact

• Excellent English communication skills

• Experience collaborating in cross-functional teams (ranking, product, data engineering)

Benefits:

• Work with smart and empathetic people who will help you grow and make a meaningful impact.

• Regular team offsite events to connect and collaborate.

• Fully remote team - choose where you live.

• Unlimited vacation time - we strongly encourage all of our employees take at least 3 weeks per year.

• Work from home stipend! We want you to have the resources you need to set up your home office.

• Apple laptops provided for new employees.

• Training and development budget for every employee, refreshed each year.

• Maternity & Paternity leave for qualified employees.

• Base salary: $80k–$120K USD, depending on knowledge, skills, experience, and interview results.

• Stock options - offered in addition to the base salary.

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