About the role

Senior Staff Engineer owning search, ranking, and recommendations for Cantina’s social AI platform. Setting technical direction across discovery, feeds, personalization, and OpenSearch.

Responsibilities

Own the architecture and roadmap for search and recommendations, including query understanding, retrieval, ranking, search, discovery, home feed, trending, and creator leaderboards
Define quality metrics per surface, build offline evaluation and golden-set tooling, and run online experiments
Design and evolve ranking systems, including engagement signal pipelines, decay and freshness models, and index-time/live query-time signal combination
Own OpenSearch in production, including index and mapping design, reindex and cutover safety, query performance, cost, and cluster capacity
Build candidate generation and personalization for recommendation surfaces and partner with data and ML on feature pipelines and models
Collaborate with Product and Trust & Safety on quality gates, cold-start behavior, and recommendation safety
Establish instrumentation, flag-gated rollouts, and runbooks
Serve as technical point of contact for discovery across backend teams and mentor engineers

10+ years building production software, with substantial depth in search, ranking, recommendations, or ML-driven relevance on a consumer-scale product
Hands-on expertise with a production search engine such as OpenSearch, Elasticsearch, Lucene, Vespa, or similar, including index and analyzer design, relevance tuning, and cluster operations
Experience owning offline evaluation, golden sets, and A/B or interleaving frameworks
Fluency across candidate generation, feature pipelines, embedding retrieval, and re-ranking
Strong distributed systems and backend fundamentals
Production experience in Go or a comparable systems language
Comfort with SQL warehouses and streaming and batch pipelines
Demonstrated ownership of an ambiguous area with measurable results
Clear written communication and judgment regarding relevance, freshness, safety, and latency tradeoffs
Preferred: experience with AI-generated or rapidly growing content catalogs, severe cold-start conditions, or ranking under trust-and-safety constraints

Generous company equity
Medical, dental, and vision insurance – 99.99% of premiums covered by Cantina
42 days of paid time off, including 15 PTO days, 10 sick days, 15 company holidays, and 2 floating holidays
Generous parental leave & fertility support
401(k) retirement savings plan
Lifestyle spending account – $500/month to use however you’d like
Complimentary lunch and snacks for in-office employees
One Medical membership