{"id":1726941,"url":"https://alion.io/job/handshake-senior-software-engineer-annotations","title":"Senior Software Engineer, Annotations","company":{"id":5000,"name":"Handshake","domain":"joinhandshake.com","url":"https://alion.io/company/handshake","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":90,"open_postings":10,"ghost_share":0,"stale_share":0.4,"repost_share":0,"time_to_fill_p50_days":50,"computed_at":"2026-10-05T05:45:15Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","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":208000,"max":260000,"currency":"USD","period":"year","gross":null,"usd_annual":260000},"salary_estimate":null,"experience_years_min":6,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Node JS","optional":false},{"name":"Post-training","optional":false},{"name":"PostgreSQL","optional":false},{"name":"Python","optional":false},{"name":"React.js","optional":false},{"name":"TypeScript","optional":false},{"name":"Human-in-the-Loop","optional":true},{"name":"JavaScript","optional":true},{"name":"Scale AI","optional":true}],"status":"live","first_seen_at":"2026-10-02T19:18:21Z","employer_posted_date":"2026-10-02","last_verified_at":"2026-10-06T00:46:58Z","board_verified":true,"closed_at":null,"days_open":3,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":3},"description":"About Handshake\nHandshake was founded on a simple belief that everyone deserves a path to a great career, regardless of where they went to school or who they know. Today, we power 25 million job seekers, 1 million+ employers, and 1,600 educational institutions.\nAbout Handshake AI\nHuman data is the core infrastructure to AI advancement. Frontier AI labs currently improve model capabilities with various data-intensive post-training techniques. We believe that data spend for AI training will increase by 3-5x in the next few years and continue for much longer as models take on new domains. Handshake AI supports all of the frontier AI labs, working on their most complex data at the largest scale.\nThe Role\nWe’re looking for a Senior Software Engineer to join our Annotations team and build the systems that power high-quality human data for frontier AI companies. You’ll work at the intersection of product engineering, distributed systems, and AI data operations-designing tools that help operators manage annotation projects, improve task quality, and scale expert workflows.\nThis is a high-ownership role in a fast-moving environment. You’ll partner closely with product, design, data, operations, and engineering teams to turn ambiguous problems into reliable, intuitive software used across the annotation lifecycle.\nWhat you’ll do\nBuild and scale operator tooling that enables teams to create, manage, prioritize, and audit annotation projects.\n\nDesign workflows and quality-control systems that improve task accuracy, throughput, and customer outcomes.\n\nDevelop performant full-stack features using Python, Node.js/TypeScript, React, PostgreSQL, and backend APIs.\n\nEstablish technical direction for complex projects, balancing speed, maintainability, reliability, and operational needs.\n\nPartner with product, design, operations, and data teams to define requirements and ship impactful solutions.\n\nLead projects from initial concept through high-quality production delivery, including rollout, monitoring, and iteration.\n\nMentor engineers, raise the quality of code reviews and architecture discussions, and help unblock the team.\n\nImprove engineering processes, testing practices, observability, and operational health across the squad.\n\nYou have\n6+ years of software engineering experience building and operating production systems.\n\nStrong proficiency in Python, Node.js, Typescript, React, PostgreSQL, and backend APIs.\n\nExperience designing scalable, reliable software and making sound architectural tradeoffs.\n\nA track record of owning complex projects from ambiguity through delivery.\n\nStrong product judgment and an ability to connect technical decisions to customer and business outcomes.\n\nExcellent communication skills and the ability to work effectively with technical and non-technical partners.\n\nA quality mindset: you write maintainable code, test thoughtfully, debug deeply, and address root causes.\n\nA collaborative leadership style, including experience mentoring engineers and elevating team practices.\n\nComfort working in a high-velocity environment where priorities and requirements evolve quickly.\n\nBonus points\nExperience building workflow, marketplace, operations, or internal-platform software.\n\nFamiliarity with AI/ML data pipelines, annotation systems, evaluation workflows, or human-in-the-loop products.\n\nExperience working with distributed teams, expert networks, or high-volume operational processes.\n\nContributions to open source or a strong record of self-directed technical projects.\n\nWe offer\nHandshake delivers benefits that help you feel supported and thrive at work and in life. Benefits for full-time US employees include:\nEquity in a fast-growing company\n\n401(k) match, competitive compensation, and financial coaching\n\nMedical, dental, and vision coverage\n\nMental health support and a $500 wellness stipend\n\nPaid parental leave, fertility benefits, and parental coaching\n\n$2,000 annual learning stipend\n\nFlexible PTO, 15 holidays, and 2 flex days\n\nInternet, commuting support, and free lunch and gym access in our San Francisco office\n\nTeam outings and referral bonuses\n\nExplore our mission, values, and comprehensive US benefits at joinhandshake.com/careers.\nWhy join Handshake now:\nShape how every career evolves in the AI economy, at global scale, with impact your friends, family and peers can see and feel\n\nPartner hand-in-hand with world-class AI labs, Fortune 500 partners and the world’s top educational institutions\n\nWork together with engineers, scientists, operators, and more from Palantir, Meta, Scale AI, and former YC founders\n\nBuild a massive, fast-growing business with billions in revenue","description_format":"text","description_chars":4659,"description_truncated":false,"requirements":{"experience_years_min":6,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Equity","Parental leave"],"hiring_locations":[],"hiring_excludes":[],"relocation_offered":false,"industries":["Artificial Intelligence"],"lifecycle":[{"event":"open","at":"2026-10-02T22:27:08Z"}],"visa":[],"liveness":{"score":90,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.903,"p_room":1,"age_days":2,"expected_fill_days":50,"reasons":["conf:1","velocity","win:early"],"computed_at":"2026-10-05T05:45:15Z"},"pay":{"stated_usd_annual":260000,"is_top_pay":true},"html_url":"https://alion.io/job/handshake-senior-software-engineer-annotations","json_url":"https://alion.io/job/handshake-senior-software-engineer-annotations.json","meta":{"generated_at":"2026-10-06T01:40:24Z","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","counted_by":"address","units_charged":1,"used_today":2383,"day_limit":5000,"remaining_today":2617,"minute_limit":60,"resets_at":"2026-10-07T00:00:00Z"}},"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":5000},"rest":"https://alion.io/mcp/rest/get_company?id=5000"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fhandshake-senior-software-engineer-annotations"},{"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%2Fhandshake-senior-software-engineer-annotations"},{"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%2Fhandshake-senior-software-engineer-annotations"},{"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/handshake-senior-software-engineer-annotations\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fhandshake-senior-software-engineer-annotations"}]}