{"id":16526,"url":"https://alion.io/job/mercor-machine-learning-engineer-marketplace","title":"Software Engineer, Machine Learning","company":{"id":4960,"name":"Mercor","domain":"mercor.com","url":"https://alion.io/company/mercor","size_band":"1001-5000","is_staffing_agency":false,"employer_type":"direct","is_intermediary":true,"listed_via":null,"ats_vendor":"Ashby","truth_index":{"grade":"A","score":88,"open_postings":15,"ghost_share":0,"stale_share":0.267,"repost_share":0,"time_to_fill_p50_days":76,"computed_at":"2026-10-29T05:49:05Z"}},"role":"AI/ML","role_family":"AI/ML","seniority":null,"employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["San Francisco, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":160000,"max":500000,"currency":"USD","period":"year","gross":null,"usd_annual":500000},"salary_estimate":null,"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":true,"technologies":[{"name":"Embeddings","optional":false},{"name":"Machine Learning","optional":false},{"name":"Apache Kafka","optional":true},{"name":"ElasticSearch","optional":true},{"name":"Fine-tuning","optional":true},{"name":"Kubernetes","optional":true},{"name":"PostgreSQL","optional":true},{"name":"Python","optional":true},{"name":"RAG","optional":true},{"name":"Redis","optional":true},{"name":"Terraform","optional":true}],"status":"live","first_seen_at":"2026-06-30T18:51:02Z","employer_posted_date":"2026-06-30","last_verified_at":"2026-10-29T22:31:45Z","board_verified":true,"closed_at":null,"days_open":121,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":121},"description":"About Mercor\nMercor's mission is to organize human intelligence to power the AI economy. We're a leading AI data company, building the layer between human expertise and frontier models. Millions of domain experts on the platform are paid over $4 million per day to train frontier AI models. Mercor's APEX benchmark family measures AI's real-world impact on professional work. Mercor Enterprise brings this same infrastructure to Fortune 500 companies: helping companies capture how their best people actually work, translating that expertise directly back into agents.\nMercor is creating a new category of work where expertise powers AI advancement. Achieving this requires an ambitious, fast-paced and deeply committed team. You’ll work alongside researchers, operators, and AI companies at the forefront of shaping the systems that are redefining society. Mercor is a profitable Series C company valued at $10 billion. We work in-person five days a week in our San Francisco, NYC, or London offices.\nAbout the Role\nAs a Machine Learning Engineer on the Marketplace team, you will build the models and decision systems that power Mercor's hiring engine. This includes search and ranking, candidate-job matching, marketplace recommendations, personalization, and allocation decisions across a rapidly growing talent network.\nThis is an applied ML role with direct product and revenue impact. You will work on problems shaped by real marketplace constraints: sparse and delayed labels, cold start, noisy feedback, heterogeneous supply and demand, and the need to optimize across speed, quality, and conversion simultaneously.\nWhat You'll Build\nRanking and matching systems that determine which candidates and opportunities are surfaced\n\nModels for recommendation, personalization, and marketplace optimization\n\nRetrieval, scoring, and decision pipelines operating at global scale\n\nFeedback loops that learn from downstream hiring outcomes, not just top-of-funnel engagement\n\nReal-time and batch inference systems embedded in product-critical workflows\n\nExample Problems\nImprove candidate-job matching using embeddings, structured attributes, and behavioral signals\n\nOptimize ranking toward long-term hiring outcomes under delayed and incomplete labels\n\nDesign models that balance marketplace objectives such as fill rate, quality, speed, and conversion\n\nBuild systems for candidate allocation, opportunity routing, and liquidity optimization\n\nDevelop evaluation and experimentation frameworks that connect model performance to business results\n\nWhat We're Looking For\nStrong track record of shipping ML systems into production\n\nExperience with ranking, recommendation, search, matching, or marketplace problems\n\nGood judgment on model design, objective functions, evaluation, and tradeoffs\n\nComfort working across the full applied ML stack: data, features, training, inference, and iteration\n\nStrong engineering fundamentals and a bias toward simple, robust systems\n\nWhy This Role\nThis role sits on a core decision layer of the product. Your work will directly shape how talent is discovered, matched, and hired, and will influence fundamental marketplace outcomes across quality, speed, and revenue.\nTech Stack\nPython, Go, embeddings, fine-tuning, RAG, Kafka, Postgres, Redis, Elasticsearch, Kubernetes, Terraform\nBenefits\nBi-annual performance bonus structure\n\nGenerous equity grant vested over 4 years\n\nUp to $15k Relocation bonus\n\n$10K housing bonus (if you live within 0.5 miles of our office)\n\n$1.5K monthly stipend for meals\n\nFree Equinox membership\n\n$200 monthly laundry reimbursement\n\n$200 monthly personal wellness reimbursement\n\nHealth, Dental, Vision insurance","description_format":"text","description_chars":3671,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Equity","Vision insurance"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":true,"industries":["Recruiting & Staffing","Freelance & Talent Marketplaces","AI Training Data & Annotation"],"lifecycle":[{"event":"open","at":"2026-06-30T18:51:02Z"}],"visa":[],"liveness":{"score":20,"band":"cold","label":"Long shot","p_open":1,"p_active":0.55,"p_room":0.36,"age_days":120,"expected_fill_days":76,"reasons":["conf:0","velocity","win:tail","crowd:brand"],"computed_at":"2026-10-29T05:49:05Z"},"pay":{"stated_usd_annual":500000,"is_top_pay":true},"html_url":"https://alion.io/job/mercor-machine-learning-engineer-marketplace","json_url":"https://alion.io/job/mercor-machine-learning-engineer-marketplace.json","meta":{"generated_at":"2026-10-30T00:02:04Z","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":51,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-31T00:00:00Z"}},"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":4960},"rest":"https://alion.io/mcp/rest/get_company?id=4960"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fmercor-machine-learning-engineer-marketplace"},{"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%2Fmercor-machine-learning-engineer-marketplace"},{"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%2Fmercor-machine-learning-engineer-marketplace"},{"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/mercor-machine-learning-engineer-marketplace\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fmercor-machine-learning-engineer-marketplace"}],"agent":{"mcp":"https://alion.io/mcp/jobs","mcp_open":"https://alion.io/mcp/open","next":[{"tool":"get_job","arguments":{"id":16526}},{"tool":"search_jobs","arguments":{"company":"mercor.com","detail":"compact"}},{"tool":"match_people","arguments":{"job_id":16526},"note":"people open to offers who fit this vacancy"}],"note":"The same data through MCP tools: https://alion.io/mcp/open needs no sign-in (compact searches, postings, people); https://alion.io/mcp with an Alion account has everything. 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