Machine Learning Engineer

<h2><strong>About the role</strong></h2><p style="min-height:1.5em">Linkup is the web search engine built for AI. Our infrastructure crawls, indexes and serves the live web to AI agents, and it’s scaling fast.</p><p style="min-height:1.5em">We’re looking for a top‑tier <strong>Machine Learning Engineer</strong> to join Linkup and work hand‑in‑hand with our CTO, <a target="_blank" rel="noopener noreferrer nofollow" href="https://www.linkedin.com/in/denis-charrier/">Denis Charrier</a>, and the rest of the tech team.</p><p style="min-height:1.5em">Your core responsibilities will be to:<br />Design, train and ship ranking and retrieval models for AI agents</p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Design, train and ship ranking and retrieval models for AI agents</p></li><li><p style="min-height:1.5em">Bring new ranking signals into the engine, beyond pure relevance</p></li><li><p style="min-height:1.5em">Build the evaluation framework that tells us what really improves search quality</p></li><li><p style="min-height:1.5em">Optimize model serving for latency and GPU cost</p></li><li><p style="min-height:1.5em">Turn customer and benchmark feedback into ranking improvements, with clear before/after numbers</p><div style="min-height:1.2em;margin-top:0px;margin-bottom:0px"> </div></li></ul><div style="min-height:1.2em;margin-top:0px;margin-bottom:0px"> </div><h2><strong>Requirements</strong></h2><p style="min-height:1.5em">You’re a great match if you:</p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Are excited to help build Google for AI agents- and believe in <a target="_blank" rel="noopener noreferrer nofollow" href="https://www.notion.so/Join-Linkup-9a304f74df4544bf83d9b23c3b31b699?pvs=21">Linkup’s mission</a></p></li><li><p style="min-height:1.5em">Have strong hands-on experience in information retrieval, ranking or search in production.</p></li><li><p style="min-height:1.5em">Build rigorous evals and check the data behind every number</p></li><li><p style="min-height:1.5em">Care about latency, cost and reliability as much as model quality</p></li><li><p style="min-height:1.5em">Thrive in a fast-paced, high-ownership startup environment</p></li></ul><div style="min-height:1.2em;margin-top:0px;margin-bottom:0px"> </div><h2><strong>Example Projects</strong></h2><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Ship a new ranking model to production and prove the gain on our eval sets</p></li><li><p style="min-height:1.5em">Push our models to the next level: better answers, lower latency, lower cost per query</p></li><li><p style="min-height:1.5em">Build and maintain the evaluations framework that measures every change to our search engine</p></li></ul><div style="min-height:1.2em;margin-top:0px;margin-bottom:0px"> </div><h2><strong>Our Stack</strong></h2><p style="min-height:1.5em">Python, PyTorch, Hugging Face, vLLM, Ray, Spark / Databricks, Vespa, Kubernetes, GitHub Actions, Terraform</p><p style="min-height:1.5em"></p><h2><strong>Details</strong></h2>