Machine Learning Engineer, Ranking & Retrieval

This is a fully remote position, open to applicants in United States.

📋 Description

• Take ownership of the complete machine learning lifecycle for ranking and retrieval, encompassing training, deployment, and production serving.

• Develop ranker features, training pipelines, and offline evaluation frameworks.

• Design and enhance hybrid retrieval systems that merge lexical and vector search, including HNSW with disk offloading.

• Execute embedding inference at a scale involving billions of documents.

• Enhance query comprehension via intent modeling and query expansion techniques.

• Construct permissions-aware retrieval systems that adhere to multi-tenant boundaries.

• Establish measurement frameworks to assess and elevate search quality.

• Work collaboratively with Search Infrastructure, AI, and backend teams to implement ranking enhancements across the platform.

⛳️ Requirements

• A Bachelor's degree in Computer Science, Machine Learning, or a related discipline.

• Over 5 years of ML engineering experience with a focus on ranking, retrieval, or information retrieval.

• Demonstrated ownership of the full ML lifecycle: training, deploying, and serving models in a production environment.

• Practical experience in ranker model training, including feature engineering, pipelines, and offline evaluation.

• Proven experience in constructing hybrid retrieval systems (lexical + vector).

• Skilled in executing embedding inference at a large scale.

• Strong foundational knowledge in query understanding, including intent modeling and query expansion.

• Experience with permissions-aware retrieval and multi-tenancy.

• Expertise in indexing large-scale user-generated content.

• Hands-on experience with OpenSearch or Elasticsearch.

• Proficient in sharding, index management, and real-time ingestion at scale.

• Background in natural language processing, semantic search, or agentic retrieval.

• Experience with TypeScript in backend systems.

🏝️ Benefits

• Equity

• 401k

• Health, Dental, and Vision insurance

• Spending accounts

• Life & Disability insurance

• Paid parental leave

• Flexible paid time off

• Enhanced employee assistance program

• Employee wellness stipend

• Professional development stipend