Senior Backend Engineer

Senior Backend Engineer LocationNYC (NY), San Francisco (CA) or Paris (FR)Employment TypeFull timeDepartmentTechAbout the roleWe’re looking for a top‑tier Backend Engineer to join our tech team and work hand‑in‑hand with our CTO, Denis Charrier, and the rest of the tech team.Your core responsibilities will be to:Build and operate large-scale, distributed systems powering AI-ready web searchDevelop APIs, data pipelines, and microservices for indexing, retrieval, and monitoringOptimize performance, scalability, and resource usage across our stackParticipate in architecture discussions and contribute to system designCollaborate with ML and product teams to deliver data-driven featuresWrite clean, maintainable code and participate in code reviewsRequirementsYou’re a great match if you:Are excited to help build Google for AI agents- and believe in Linkup’s missionHave strong experience in backend development (3y minimum)Understand distributed systems, caching, and data storage internalsCare about performance, reliability, and code qualityEnjoy debugging tough production issues and optimizing performance bottlenecksAre curious about AI infrastructure and retrieval systemsThrive in a fast-paced, high-ownership startup environmentExample ProjectsIndex hundred of millions of web pages every day, with < 5 min freshnessAdd multimodal search (text + images + audio) under 150 msStream 1 B embeddings / day for while minimizing compute costsAuto‑retrain ranking on agent clicks every 24 hOur StackNode.js / NestJSPythonJavaPostgreSQLOpenSearchVespaApache StormKubernetesGitHub ActionsTerraformDetailsThe ideal candidate will play a central role in our engineering team, partnering closely with the founders to spearhead groundbreaking products. Your backend expertise will shape the future of AI‑powered applications and bring our vision to life.We offer a flexible remote‑work policy- see the details here.Join us and leverage your expertise to push the boundaries of AI!About LinkupOur VisionWe believe in a future of AI agents and the agentic web. These digital entities can create more value for humanity than we ever could alone, but they depend on the internet to operate, collaborate, take action, and gather information.AI agents need web search. To perform well, they require information that is current, reliable, and context‑specific—not the diffuse, steadily aging knowledge frozen at their last training cut‑off.Modern web search is built for humans, not AIs. Instead of trusted facts, it serves links, ads, and click‑bait. People want visually engaging pages; AI systems need structured truth. An AI can absorb oceans of data, while human attention barely skims the surface. Humans think visually and intuitively; AI reasons in latent space.Web 2.0 is sunsetting. The deck is being reshuffled, and the Bing‑Google search oligopoly is crumbling. Indexing ever more pages is no longer the goal; semantically organizing facts for AI systems is. In the coming agentic web, Google’s ad‑driven model has no natural home.Search for AI must be rebuilt from the ground up. We are reconstructing the web as a rigorously structured knowledge layer, mapping every concept, entity, and claim into a coherent semantic graph. This foundation delivers verified facts and rich context to AI instantly, unlocking faster reasoning, higher accuracy, and radically more useful answers for everyone.Humans search Google; AI searches Linkup.Our MissionReality never stands still, and neither should intelligence. Linkup reconnects language models to a living stream of verified facts, ensuring AIs remain as current and insightful as the world they serve.Our mission is to deliver the world’s freshest, most trusted knowledge to AIs.Our CultureOur culture is built on the following values:Mission. We believe we play a critical role in building the agentic web. We are 100% committed to our mission of bringing the reality of the world to AI agents.Speed. We build fast, we build to last. We get...