{"id":14866,"url":"https://alion.io/job/retell-ai-senior-software-engineer-backend","title":"Senior Software Engineer, Backend","company":{"id":4592,"name":"Retell AI","domain":"retellai.com","url":"https://alion.io/company/retell-ai","size_band":"51-200","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":{"grade":"B","score":81,"open_postings":9,"ghost_share":0,"stale_share":0.778,"repost_share":0,"time_to_fill_p50_days":39,"computed_at":"2026-10-17T05:46:00Z"}},"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":"explicit","locations":["San Francisco, United States"],"countries":["US"],"hiring_countries":[],"hiring_countries_total":0,"salary":{"min":200000,"max":300000,"currency":"USD","period":"year","gross":null,"usd_annual":300000},"salary_estimate":null,"experience_years_min":2,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"AI Agents","optional":false},{"name":"Voice Agents","optional":false},{"name":"JavaScript","optional":true},{"name":"Node JS","optional":true},{"name":"Python","optional":true},{"name":"React.js","optional":true}],"status":"live","first_seen_at":"2024-12-03T19:32:33Z","employer_posted_date":"2024-12-03","last_verified_at":"2026-10-17T15:03:07Z","board_verified":true,"closed_at":null,"days_open":682,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":682},"description":"ABOUT RETELL AI\nRetell AI is using first-principles thinking to reimagine the call center with cutting-edge voice AI. Thousands of companies now use Retell's AI voice agents to handle sales, support, and logistics calls that once required large teams of human agents. Backed by Y Combinator, Alt Capital, and other leading investors, we've scaled to $80M in ARR with a team of 50, up from $5M at the start of 2025, and are now valued at over $1.5B.\nOur vision for 2026 is to build a modern CX platform where entire contact centers are powered by AI. Instead of basic automation that needs constant human tuning, we're creating intelligent AI “workers” that act as frontline agents, QA analysts, and managers, continuously executing, monitoring, and improving every customer interaction.\nWe're growing fast and looking for ambitious builders who want to tackle hard technical problems, move quickly, and have a real impact on one of the fastest-growing voice AI companies in the world.\nLet's build the future together.\nRecent recognition:\nNo. 1 Best Places to Work in the Bay Area, San Francisco Business Times 2026\n\nTop 50 AI Apps, a16z (2025)\n\n#3 Fastest-Growing Software Company, G2 Best Software Awards 2026\n\nBest Agentic AI Software, G2 Best Software Awards 2026\n\n#4 Fastest-Growing Software Vendor, Brex Benchmark 2025\n\nEnterprise Tech 30 Class of 2026, Nasdaq & Wing VC\n\nTop-Ranked Startup, Lean AI Leaderboard\n\nBacked by Y Combinator\n\nABOUT THE ROLE\nRetell AI transforms customer experience with voice AI for enterprises, including customers like CVS/Aetna, American Airlines, Lenovo, and Grab. We have more customer stories than we can tell!\nAs a Senior Backend Engineer, you’ll shape the core systems powering millions of AI-driven conversations. You’ll tackle real-time audio, global telephony, and developer tooling, working across the stack with the founding team. This high-impact role offers rapid feedback loops, customer collaboration, and the chance to define a category-leading product.\nKEY RESPONSIBILITIES\nBuild foundational architecture for Retell's platform, such as prompt orchestration, testing frameworks, observability dashboards, and telephony integrations.\n\nDesign scalable backend systems and DevOps workflows for reliable performance across millions of calls.\n\nLead complex projects from architecture to production, driving delivery and monitoring.\n\nCollaborate with product and design teams to create intuitive APIs and interfaces for quick customer onboarding.\n\nSupport customer onboarding, troubleshoot issues, and turn feedback into product improvements.\n\nYOU MIGHT THRIVE IF\nHave 2+ years of backend development experience and a strong foundation in CS fundamentals (CS/CE/EE degree or equivalent).\n\nHave worked on scalable, high-performance backend systems, especially anything involving concurrency, data, storage, or distributed components.\n\nTake ownership like a founder and enjoy building core systems that need to be fast, reliable, and correct.\n\nThrive in fast-moving, ambiguous environments where you learn quickly and solve new technical problems.\n\nCommunicate clearly, collaborate well across teams, and move work forward with momentum.\n\nHave startup experience or the grit to operate in a high-velocity environment, bonus points if you’ve worked on infrastructure, databases, or large-scale backend systems.\n\nJOB DETAILS\nCash: 200k - 300k\n\nEquity: Offer Equity\n\nLocation: Redwood City, CA, US\n\nUS Visas: Retell AI is open to sponsoring work authorization for qualified candidates, including H-1B, TN, L-1, E-3, F-1 (OPT/CPT), and O-1 visas.\n\nOTHER BENEFITS\n100% coverage for medical, dental, and vision insurance\n\n$70/day DoorDash credit for unlimited breakfast, lunch, dinner, and snacks\n\n$200/month wellness reimbursement (gym, fitness classes, etc.)\n\n$300/month commuter reimbursement (gas, Caltrain, etc.)\n\n$75/month phone bill reimbursement\n\n$50/month internet reimbursement\n\nCOMPENSATION PHILOSOPHY\nBest Offer Upfront: Choose from three cash-equity balance options; no negotiation needed.\n\nTop 1% Talent: Above-market pay (top 5 percentile) to attract exceptional builders.\n\nHigh Ownership: Small teams, >$1M revenue/employee, and significant equity.\n\nPerformance-Based: Offers tied to interview performance, not experience or past salaries.\n\nINTERVIEW PROCESS\nIntro Call (15-20min): Connect with our Recruiter to get a deeper look at the team and the work you'd be doing.\n\nTechnical Interview (45 min): Practical coding session focused on code fluency and system design (For frontend roles, we will focus on React-specific questions. For backend roles, we take a technology-agnostic approach.)\n\nTechnical Interview (45 min): A system design-focused interview assesses your knowledge of building product-ready systems.\n\nOnsite/Virtual Interviews (2-3 hrs): Hosted in our office if located in the Bay Area or virtual, with three rounds:\nPractical Coding: Tackle real-world coding tasks with debugging.\n\nSystem Design: Architect a production-ready system.\n\nTools & Automation: Build automations or improve workflows in any basic environment setup like python, java, node.js, etc.","description_format":"text","description_chars":5129,"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":["Equity","Internet reimbursement","Vision insurance"],"hiring_locations":[{"name":"United States","iso":"US","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Conversational AI","Speech & Audio AI","AI Agents","Contact Center Software"],"lifecycle":[{"event":"open","at":"2024-12-03T19:32:33Z"},{"event":"open","at":"2026-09-25T18:08:30Z"}],"visa":[{"country":"US","licensed_sponsor":true,"evidence":"H-1B filings in 12 months: 12","filings_12m":12,"filings_prev_12m":3,"green_card_filings_12m":0,"median_offered_wage_usd":248750,"route":null,"cap_exempt":false,"checked_at":"2026-10-15T11:24:14+00:00","sources":["US Department of Labor: LCA disclosure data (H-1B, H-1B1, E-3)"],"filings_for_role_12m":10}],"liveness":{"score":8,"band":"cold","label":"Long shot","p_open":1,"p_active":0.277,"p_room":0.28,"age_days":682,"expected_fill_days":39,"reasons":["conf:0","win:tail","crowd:"],"computed_at":"2026-10-17T05:46:00Z"},"pay":{"stated_usd_annual":300000,"is_top_pay":true},"html_url":"https://alion.io/job/retell-ai-senior-software-engineer-backend","json_url":"https://alion.io/job/retell-ai-senior-software-engineer-backend.json","meta":{"generated_at":"2026-10-17T16:02:31Z","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":21853,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-18T00:00:00Z"}},"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":4592},"rest":"https://alion.io/mcp/rest/get_company?id=4592"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Fretell-ai-senior-software-engineer-backend"},{"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%2Fretell-ai-senior-software-engineer-backend"},{"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%2Fretell-ai-senior-software-engineer-backend"},{"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/retell-ai-senior-software-engineer-backend\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Fretell-ai-senior-software-engineer-backend"}]}