{"id":723439,"url":"https://alion.io/job/cheiron-backend-engineer-applied-agents-los-altos","title":"Backend Engineer, Applied Agents (Los Altos)","company":{"id":673520,"name":"Cheiron","domain":"cheiron.bio","url":"https://alion.io/company/cheiron","size_band":"51-200","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":{"grade":"A","score":95,"open_postings":9,"ghost_share":0,"stale_share":0,"repost_share":0,"time_to_fill_p50_days":91,"computed_at":"2026-10-26T05:57:25Z"}},"role":"Backend","role_family":"Backend","seniority":"junior","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Los Altos, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":94000,"max_usd":195000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":1118},"experience_years_min":2,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Claude Code","optional":false},{"name":"Cursor","optional":false},{"name":"FastAPI","optional":false},{"name":"Function Calling","optional":false},{"name":"LLM","optional":false},{"name":"PostgreSQL","optional":false},{"name":"Python","optional":false},{"name":"RAG","optional":false},{"name":"Semantic Search","optional":false},{"name":"AI Agents","optional":true},{"name":"AWS","optional":true},{"name":"Kubernetes","optional":true},{"name":"LangChain","optional":true},{"name":"LangGraph","optional":true},{"name":"Terraform","optional":true}],"status":"live","first_seen_at":"2026-06-24T02:01:37Z","employer_posted_date":"2026-06-24","last_verified_at":"2026-10-26T09:16:02Z","board_verified":true,"closed_at":null,"days_open":124,"trust":{"level":"ok","repost_count":0,"flags":[],"days_open":124},"description":"Cheiron just raised an $8 million seed round led by Menlo Ventures to build the operating system for drug programs.\n\nCompany Overview\nIn July 2026, Cheiron announced an $8 million seed round led by Menlo Ventures, bringing total funding to $13 million to date, with the backing and strategic support of industry veterans including Moderna co-founder and MIT Institute Professor Robert Langer, former Pfizer Chief Medical Officer Freda Lewis-Hall, Chai Discovery co-founder and CEO Josh Meier, former Starbucks CEO Laxman Narasimhan, and former Apple AI chief John Giannandrea.\nCheiron is building the first AI-native operating system designed to represent an entire drug program as a single connected system. The company's platform helps biopharma teams represent, reason over, and stress-test the full state of a drug development program, including the claims, evidence, assumptions, risks, decisions, and commitments that determine whether a therapy advances. In less than six months since launch, Cheiron has been adopted by tens of thousands of biopharma professionals and deployed by major drug developers, and is already used by 7 of Korea's top 10 biopharma companies.\nCheiron is expanding into pharmaceutical CMC (Chemistry, Manufacturing, and Controls) teams. CMC governs how a drug is made, tested, and kept consistent across its entire commercial life. The work involves hundreds of regulatory commitments, post-approval changes, and cross-market submissions. Today it runs on documents, spreadsheets, and institutional memory. Cheiron augments manual workflows with a CMC regulatory-specific intelligence and reasoning layer.\nFounded in 2024 by Stanford-trained AI researchers. The team includes leaders with combined decades of experience across pharma and biotech. Headquartered in Los Altos, California. We are building and deploying the product now with rapid expansion into global markets.\n\nAbout the Role\nWe're looking for a Backend Engineer, Applied Agents to help build Cheiron's agent layer and the backend systems that power it.\nCheiron's agents don't just generate answers. They carry out multi-step tasks inside real drug development workflows, call tools reliably, execute code in sandboxed environments, retain context across multi-step work, and deliver verifiable results to users. You'll design and ship the agent runtime, harness, memory, and tool execution layers that make all of this possible.\nWe build products that run in real customer environments - not research demos or prototypes. We're looking for a hands-on builder who can quickly structure ambiguous problems and turn them into highly polished products. You don't need to be an AI researcher or a life sciences domain expert, but we care deeply about strong engineering fundamentals and real experience designing, building, and operating LLM systems.\n\nWhat You'll Do\nDesign, build, and operate Cheiron's agent layer: agent runtime/harness, tool-calling infrastructure, sandboxed code execution, agent memory, and the reliability and observability of multi-step tasks\n\nDesign and build backend services and APIs on Python, FastAPI, and Postgres\n\nDesign and operate vector DB, semantic search, and RAG systems, and tune search quality and latency\n\nBuild large-scale ingestion, cleaning, and indexing pipelines for life sciences data, including academic papers, clinical, regulatory, safety, and patent sources\n\nBuild systems that ground AI-generated outputs in source data with traceable, verifiable citations so they can be trusted in real pharma and biotech work\n\nWork directly with founders, domain experts, and early customers, owning outcomes rather than just closing tickets\n\nRequirements\n2+ years of experience shipping and operating production backend systems end to end\n\nStrong backend engineering fundamentals: a deep understanding of API design, data modeling, databases, and system reliability\n\nHands-on production experience with AI-driven systems such as LLMs, RAG, and vector DBs\n\nPractical understanding of how agent systems actually work: you've built - or at least deeply traced - agent runtimes, harnesses, tool calling, sandboxing, and memory\n\nThe drive to set your own priorities and ship quickly, even when specs are incomplete\n\nA balance of fast shipping velocity and sound engineering judgment\n\nActive use of AI coding tools such as Claude Code and Cursor\n\nNice to Have\n(Most important) Experience building an in-house agentic harness: if you've designed and built internal tools or harnesses to boost your team's agentic development productivity, that's the strongest signal for us\n\nHands-on experience designing and operating LangGraph, agent frameworks, or RAG systems in production\n\nExperience building enterprise SaaS, or pharma, biotech, or healthcare products\n\nFamiliarity with life sciences domain data such as academic literature, clinical trials, regulatory documents, and patents\n\nExperience deploying and operating production systems on AWS, Terraform, and Kubernetes, with a focus on reliability and observability\n\nExperience at a seed or early-stage startup\n\nBenefits & Perks\n401(K) retirement plan\n\nHealth insurances (Medical/Dental/Vision)\n\nMeal allowance (Lunch, Dinner)\n\nTransportation support for early starts and late nights\n\nIn-office snack bar and additional commuting and work travel support\n\nInterview Process\nScreening ＞ Take-home Assignment ＞ Technical Interview ＞ Cultural Interview","description_format":"text","description_chars":5424,"description_truncated":false,"requirements":{"experience_years_min":2,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Health insurance","Retirement plans"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["LLM & Generative AI","Drug Discovery","Medical AI"],"lifecycle":[{"event":"open","at":"2026-09-11T07:42:18Z"}],"visa":[],"liveness":{"score":25,"band":"fade","label":"Fading","p_open":1,"p_active":0.571,"p_room":0.44,"age_days":124,"expected_fill_days":91,"reasons":["conf:1","win:tail","crowd:junior"],"computed_at":"2026-10-26T05:57:25Z"},"pay":null,"html_url":"https://alion.io/job/cheiron-backend-engineer-applied-agents-los-altos","json_url":"https://alion.io/job/cheiron-backend-engineer-applied-agents-los-altos.json","meta":{"generated_at":"2026-10-26T12:35:12Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":17268,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-27T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":673520},"rest":"https://alion.io/mcp/rest/get_company?id=673520"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fcheiron-backend-engineer-applied-agents-los-altos"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Fcheiron-backend-engineer-applied-agents-los-altos"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Fcheiron-backend-engineer-applied-agents-los-altos"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/cheiron-backend-engineer-applied-agents-los-altos\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fcheiron-backend-engineer-applied-agents-los-altos"}]}