Rebuy, Inc. is hiring a Principal Search Relevance Engineer

Rebuy, Inc. is hiring a Principal Search Relevance Engineer to be the technical authority for AI Search. In this role, you will own the search architecture, solve the hardest problems, and ship systems that power intelligent, personalized e-commerce search. Your focus will be on designing hybrid search infrastructure, implementing AI/ML systems, optimizing for scale and latency, and establishing engineering best practices.

What You'll Do

• Design the hybrid search infrastructure combining Elasticsearch for lexical matching and vector search for semantic understanding.
• Own the search architecture, including how to index, query, and serve results.
• Work on AI/ML systems: embedding model selection and fine-tuning, query understanding, intent classification, and learning-to-rank.
• Architect systems to maintain millisecond-level latency during peak traffic spikes of 10-50x load.
• Collaborate with Product Managers and Data Scientists to implement and fine-tune search relevance algorithms, NLP components, and personalization features.
• Build feedback loops, A/B testing infrastructure, and measurement systems for continuous search improvement.
• Establish, document, and promote engineering best practices, including RESTful API standards.
• Set technical standards for building search, including API contracts, data models, and system boundaries.
• Participate in code review, offer feedback, and mentor senior developers and the back-end team.

What We're Looking For

• Bachelor's degree in Computer Science, Mathematics, Engineering, or a related field.
• 8+ years of hands-on professional back-end software engineering experience.
• Deep Elasticsearch expertise, including operating it at scale and understanding analyzers, tokenizers, scoring, and BM25.
• Vector search and embeddings experience, having shipped embedding-based search in production.
• Expert proficiency in Golang (Go) and other relevant back-end languages/environments like PHP.
• Experience implementing ML systems that work at scale.
• Experience with cloud computing platforms such as AWS, GCP, or Azure.
• Familiarity with containerization using Docker and Kubernetes.
• Strong knowledge of both SQL (e.g., PostgreSQL, MySQL) and NoSQL (e.g., Redis) databases.
• Proven experience designing and implementing scalable microservices.
• Understanding of data streaming technologies for real-time indexing.
• Prior work with A/B testing frameworks for search relevance and feature rollouts.
• Ability to work both independently and as part of a team.
• Strong communication skills and ability to break down complex problems.

Nice to Have

• Master's degree strongly preferred.
• E-commerce experience.
• Experience fine-tuning embeddings on domain-specific data.
• Experience with learning-to-rank, query understanding, or recommendation systems.

Technical Stack

• Search: Elasticsearch
• Languages: Golang (Go), PHP
• Cloud: AWS, GCP, Azure
• Infrastructure: Docker, Kubernetes
• Databases: PostgreSQL, MySQL, Redis

Team & Environment

You'll join a flat structure, tight-knit, driven team. This role involves no people management.

Benefits & Compensation

• Annual compensation of $200,000 - $260,000 USD.
• 100% free health, dental, and insurance for you and your family.
• Flexible vacation policy, generous holiday schedule, parental leave, sick policy, birthday holiday.
• 401(k) retirement plans for U.S. employees with 3% contribution of gross salary.
• TFSA and RRSP retirement plans for Canadian employees with 3% contribution of gross salary.

Work Mode

This is a fully remote position for candidates based within the U.S. and Canada.

Rebuy, Inc. is proud to be an Equal Employment Opportunity employer. We do not discriminate based on gender, race or color, ethnicity or national origin, age, disability, religion, sexual orientation, gender identity or expression, veteran status, or any other applicable characteristics protected by law.