{"schemaVersion":"jobsearcher.job.v1","id":"ebbd93b6bd17e827995537fa","url":"https://jobsearcher.com/jobs/ebbd93b6bd17e827995537fa","canonicalUrl":"https://jobsearcher.com/jobs/ebbd93b6bd17e827995537fa","title":"Founding Engineer","description":"Salary range USD 130,000 - 200,000 / year\nHelping AI agents understand how attention is moving online\nAbout Upriver\nUpriver turns what’s happening across the web and social into a structured context graph of companies, people, and topics, so agents and LLM apps can catch what’s breaking out while it’s still early.\nOur customers are building at the forefront of GTM and marketing agents, including Clay and Unify. By working with them, we’ve seen firsthand the problem of getting agents fresh context that’s grounded in real-world behavior.\nWe’re backed by investors including Llama Ventures, Abstraction Capital, Corazon Capital, and angels from Instagram, Fanatics, and Clay. We have early revenue and are excited to now expand our team with our founding engineer.\nThe founders\nWe’ve spent our careers building in consumer/social and have a deep love for niche online communities, internet culture, and how attention evolves:\n\nJoe (CTO) worked on core ad infra at Spotify, was tech lead for Instagram Reels and Live, and led natural language search and image classification at Google Photos.\n\nThe role\nThis should be a great fit if you:\n\nWant to work on an open-ended problem that hasn’t been solved yet in the agent space.\nAre always tinkering and building something to solve your own problems.\n Are opinionated about the process of building, not just the outcome.\nWant the option to work closely with customers so you get to see how your product is being used in production systems.\n\nPreferred experience\n\nYou’ve built agents to solve problems.\nYou’ve built scalable data pipelines, APIs, and backend systems.\n\nSome of the technical problems you’ll tackle\n\nBuild data pipelines at huge web scale.\nLeverage multimodal and frontier data processing techniques to spot patterns, calculate historical lookbacks, and predict future patterns.\nBuild performant APIs that can handle high concurrent loads.\n\nThe role is full-time, in person in San Francisco. We work out of a coworking space in Dogpatch.\nEquity: 0.5%–2%. US citizen or visa holder only.\nThe interview process should take 1–2 weeks total\n\nIntro call with Joe (30 mins)\nOn-site interviews (2–3 hours and team lunch)\n\nContact lulu@upriver.ai or joe@upriver.ai.\nOriginal job description: https://share.upriver.ai/founding-eng\n#J-18808-Ljbffr","company":"Startx","rawCompany":"startx","city":"Millbrae","state":"CA","isRemote":false,"isActive":true,"createdAt":"2026-10-03T03:28:07.938Z","occupations":[{"code":"15-1252.00","title":"Software Developers","slug":"software-developers"},{"code":"15-1299.08","title":"Computer Systems Engineers/Architects","slug":"computer-systems-engineers-architects"},{"code":"17-2199.00","title":"Engineers, All Other","slug":"engineers-all-other"}],"industries":[{"code":"513210","title":"Software Publishers","slug":"software-publishers"},{"code":"541511","title":"Custom Computer Programming Services","slug":"custom-computer-programming-services"},{"code":"541512","title":"Computer Systems Design Services","slug":"computer-systems-design-services"}],"jobPosting":{"@context":"https://schema.org","@type":"JobPosting","title":"Founding Engineer","description":"Salary range USD 130,000 - 200,000 / year\nHelping AI agents understand how attention is moving online\nAbout Upriver\nUpriver turns what’s happening across the web and social into a structured context graph of companies, people, and topics, so agents and LLM apps can catch what’s breaking out while it’s still early.\nOur customers are building at the forefront of GTM and marketing agents, including Clay and Unify. By working with them, we’ve seen firsthand the problem of getting agents fresh context that’s grounded in real-world behavior.\nWe’re backed by investors including Llama Ventures, Abstraction Capital, Corazon Capital, and angels from Instagram, Fanatics, and Clay. We have early revenue and are excited to now expand our team with our founding engineer.\nThe founders\nWe’ve spent our careers building in consumer/social and have a deep love for niche online communities, internet culture, and how attention evolves:\n\nJoe (CTO) worked on core ad infra at Spotify, was tech lead for Instagram Reels and Live, and led natural language search and image classification at Google Photos.\n\nThe role\nThis should be a great fit if you:\n\nWant to work on an open-ended problem that hasn’t been solved yet in the agent space.\nAre always tinkering and building something to solve your own problems.\n Are opinionated about the process of building, not just the outcome.\nWant the option to work closely with customers so you get to see how your product is being used in production systems.\n\nPreferred experience\n\nYou’ve built agents to solve problems.\nYou’ve built scalable data pipelines, APIs, and backend systems.\n\nSome of the technical problems you’ll tackle\n\nBuild data pipelines at huge web scale.\nLeverage multimodal and frontier data processing techniques to spot patterns, calculate historical lookbacks, and predict future patterns.\nBuild performant APIs that can handle high concurrent loads.\n\nThe role is full-time, in person in San Francisco. We work out of a coworking space in Dogpatch.\nEquity: 0.5%–2%. US citizen or visa holder only.\nThe interview process should take 1–2 weeks total\n\nIntro call with Joe (30 mins)\nOn-site interviews (2–3 hours and team lunch)\n\nContact lulu@upriver.ai or joe@upriver.ai.\nOriginal job description: https://share.upriver.ai/founding-eng\n#J-18808-Ljbffr","datePosted":"2026-10-03T03:28:07.938Z","dateModified":"2026-10-03T03:28:07.938Z","hiringOrganization":{"@type":"Organization","name":"Startx","sameAs":"https://jobsearcher.com"},"jobLocation":{"@type":"Place","address":{"@type":"PostalAddress","addressLocality":"Millbrae","addressRegion":"CA","addressCountry":"US"}},"identifier":{"@type":"PropertyValue","name":"JobSearcher","value":"ebbd93b6bd17e827995537fa"},"url":"https://jobsearcher.com/jobs/ebbd93b6bd17e827995537fa"}}