Principal Search Relevance Engineer

Principal Search Relevance Engineer

The Company You’ll Join

At Rebuy, we're on a mission to revolutionize shopping with intelligent, personalized experiences that wow customers around the globe. As a fully remote team, we power some of the fastest growing DTC brands like Aviator Nation, Liquid Death, Magic Spoon, Blenders, Primal Kitchen, and many more.

We believe in ownership, drive, and empathy and strongly uphold that every team member plays a vital role in shaping the future of intelligent commerce. Our culture thrives on collaboration, creativity, and genuine passion. We don’t just build great tech - we build lasting partnerships, a strong community, and a place where people love to work.

The Team You’ll Join

We're a tight-knit, driven team that’s obsessed with excellence. If you thrive on curiosity, crave a challenge, and never stop learning, you’ll feel right at home here. Our flat structure means no red tape, just real impact. Everyone rolls up their sleeves and contributes directly to our mission.

We reward initiative, celebrate high performance, and believe leadership is earned through action. Strong work ethic, smart prioritization, and clear communication are must-haves. Whether you're flying solo or teaming up across departments and with customers, you'll play a key role in moving us forward.

The Problems You’ll Solve

Our Search product is the biggest technical bet we're making in 2026. Most product search is still keyword matching from 2010. A shopper types "gift for my husband who runs" and gets zero results because no product description contains those exact words.

We're building search that actually understands intent. Semantic understanding. Personalized ranking. Real-time learning. Sub-50ms latency across thousands of stores and millions of queries.

This is genuinely hard. Here's why:

• Cold start — New merchants have no behavioral data. How do you deliver great search results on day one with zero signal?

• Catalog diversity — Apparel, supplements, electronics, pet food—one search system needs to understand radically different product vocabularies and shopper intents.

• Latency vs. intelligence — More sophisticated ranking means better results but slower responses. Where's the right line? How do you push it without breaking the experience?

• Personalization at scale — How do you use behavioral signals to improve relevance without requiring months of data per shopper? How do you personalize without being intrusive?

• International expansion — Building search that supports Shopify Markets for multi-currency, multi-language, and region-specific product catalogs.

• Merchant control vs. automation — Store owners want control over their search results. AI wants to optimize. How do you build systems that respect both?

The Role

As a Principal Relevance Engineer, you'll be the technical authority for AI Search. Not a people manager. Not a project coordinator. The engineer who owns the search architecture, solves the hardest problems, and ships the systems that make it work.

• Search Architecture: Design the hybrid search infrastructure. Elasticsearch for lexical matching, vector search for semantic understanding, and the ranking layer that combines them intelligently. You decide how we index, query, and serve results.

• AI/ML Systems: Embedding model selection and fine-tuning. Query understanding and intent classification. Learning-to-rank trained on real merchant data. You work at the intersection of traditional IR and modern ML.

• System Optimization: Millions of queries across thousands of Shopify stores. Peak traffic during flash sales creates 10-50x load spikes. You architect systems that stay fast when it matters most—achieving millisecond-level latency during daily and peak e-commerce periods.

• Search Relevance: Collaborate with Product Managers and Data Scientists to implement and fine-tune search relevance algorithms, including natural language processing (NLP) components, stemming, ranking logic, and personalization features. Build the feedback loops, A/B testing infrastructure, and measurement systems that make search continuously better.

• Engineering Best Practices: Contribute significantly to Rebuy's engineering culture by establishing, documenting, and promoting best practices—including consistent RESTful API standards such as resource modeling, versioning, response structure, validation, and authentication.

• Technical Direction: Set the standards for how we build search. API contracts, data models, system boundaries. Elevate the quality of everything the team ships.

• Mentorship: Participate actively in the code review process, offering insightful and actionable feedback. Mentor senior developers and provide guidance to the back-end development team.

Who You Are

We're excited to meet you and get to learn more about you, your experience and your interest in joining our team.

The Hard Skills

• Bachelor's degree in Computer Science, Mathematics, Engineering, or a related field; Master's degree strongly preferred.

• 8+ years of hands-on professional back-end software engineering experience with a proven track record of delivering complex projects.

• E-commerce experience preferred.

• Deep Elasticsearch expertise — You've operated Elasticsearch at scale. You understand analyzers, tokenizers, scoring, and why BM25 does what it does. You've debugged relevance problems that took days to diagnose.

• Vector search & embeddings experience — You've shipped embedding-based search in production. You understand tradeoffs between architectures, dimensionality, quantization, and ANN algorithms. Experience fine-tuning embeddings on domain-specific data is valuable.

• Expert proficiency in Golang (Go) and other relevant back-end languages/environments (e.g., PHP).

• ML in production — You can read papers, evaluate approaches, and implement ML systems that actually work at scale. Experience with learning-to-rank, query understanding, or recommendation systems matters.

• Experience with cloud computing platforms (e.g., AWS, GCP, or Azure) and familiarity with containerization (Docker, Kubernetes).

• Strong knowledge of both SQL (e.g., PostgreSQL, MySQL) and NoSQL (e.g., Redis) databases, and experience optimizing complex data models.

• 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.

The Soft Skills

• Ability to work both independently and as part of a team.

• Strong communication skills and ability to break down complex problems into easy-to-understand concepts.

• Taste — You have opinions about what good search feels like. You've used products with exceptional search and understand why they work.

• Someone who carries a positive attitude, loves to be a problem-solver, is naturally self-motivated, and passionate about e-commerce.

What You Won't Do

• Write decks for stakeholders

• Ask permission to try things

• Manage people (unless you want to eventually)

Who You’ll Meet With

Now let's get into who you'll meet during our interview process! After you submit your application and it's been reviewed by our team, we will reach out to you inviting you to meet with us. From there, you can expect an interview process similar to this:

• Recruiter Screen (30 min) — Initial conversation to learn more about you and answer your questions about Rebuy and this role.

• Panel Interview (45-60 min) — Meet with members of the Search & Merchandising team to chat more in depth about your experience.

• Take Home Assignment (3-5 business days) — A project-based assessment to show us your skillset.

• Final Interviews (15 min each) — Short conversations with our CEO and COO where you'll get to learn more about Rebuy.

How We'll Evaluate You: We don't use recruiters. Your application will be reviewed by engineers. Send us your resume, a brief statement of exceptional work—one project or system you built that you're genuinely proud of and why—and optionally, a link to something you've shipped, written, or built.

The Perks You’ll Enjoy

Rebuy is a fully remote company across the U.S. and Canada that aims to provide all of our team with the resources, support and flexibility they need to thrive in their roles.

• Team: We’ve got the best, brightest, most brilliant team members who are excited to meet you! We also like to think we have a good sense of humor.

• Remote Work: With a strong internet connection, you’re able to work from anywhere within the U.S. and Canada.

• PTO: We offer a flexible vacation policy, generous holiday schedule, parental leave and sick policy. There’s other policies too like a birthday holiday!

• Amazing Benefits: 100% free health, dental, and insurance for you and your family. Don’t worry, there’s even more!

• Retirement Plans: For our U.S. employees we offer 401(k) retirement plans and for our Canadian employees we offer a TFSA and RRSP retirement plans. You’ll also enjoy a 3% contribution of your gross salary, no matter where you’re located!

Our compensation reflects the cost of labor across several U.S. geographic markets, and we pay differently based on those defined markets. The U.S. pay range for this position is $200,000 - $260,000 USD annually. Pay within this range varies by work location and may also depend on job-related knowledge, skills, and experience. Your recruiter and hiring manager can share more about the specific salary range for the job location during the hiring process.

Disclosures:

Equal Opportunity Statement

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.

Rebuy, Inc. aims to make rebuyengine.com accessible to any and all users. If you have a disability or special need that requires accommodation to navigate our website or complete the application process, email hr@rebuyengine.com.