Senior Founding Engineer

About The RoleWe're hiring a Senior Founding Engineer to help architect and scale the systems behind one of the fastest-growing platforms in conversational AI infrastructure.This is a deeply technical, architecture-heavy full stack engineering role focused on building systems that operate reliably at massive scale. The platform already handles millions of real-time conversations every month, and the engineering team is looking for someone who has built and optimized production systems operating at that level of complexity.You'll work directly with the founding team in a highly collaborative onsite environment, owning problems across the stack — from backend infrastructure and database optimization to frontend performance and real-time communication systems.This role is ideal for engineers who thrive in fast-moving startup environments, enjoy solving large-scale systems challenges, and bring exceptional craftsmanship and intensity to both work and personal pursuits.About The CompanyThe company is building the world's first quality assurance and observability platform for conversational AI agents.Founded by former AI engineers from Microsoft and AWS, the platform enables organizations to simulate, evaluate, monitor, and improve AI voice and text agents before they interact with real customers.Backed by Y Combinator, Floodgate, and PeakXV, the company has experienced explosive growth since launch:Surpassed $100K ARR within the first month during YCDoubled growth every three months since inceptionSurpassed $1M in revenueCurrently processing millions of calls monthlyCustomers include major organizations such as Google, DoorDash, Sallie Mae, and other rapidly growing enterprise customers.What You'll DoArchitecture & Systems EngineeringArchitect and develop systems for simulating, analyzing, and evaluating conversational AI agentsBuild scalable infrastructure capable of handling millions of real-time conversationsDesign resilient distributed systems using AWS services including Lambda, EC2, WebSockets, and SIPOptimize performance across the stack including database queries, APIs, and frontend rendering performanceReduce bottlenecks and improve platform responsiveness at scaleAI Infrastructure & Product DevelopmentDevelop pipelines and algorithms that surface insights, detect failures, and evaluate AI behaviorBuild systems that improve AI reliability, safety, and observabilityDevelop full stack product experiences spanning backend services and frontend applicationsWork directly with customers to deploy and improve products in real-world environmentsEngineering LeadershipEstablish strong engineering practices across architecture, system design, and code reviewContribute to technical direction and long-term scalability planningCollaborate closely with founders in a highly iterative product environmentRequired Qualifications6+ years of full stack software engineering experienceDeep expertise across both frontend and backend engineeringStrong proficiency in:TypeScriptPythonSQLAWS infrastructureStrong systems architecture and distributed systems thinkingExperience building and optimizing production systems operating at significant scaleExperience handling high-throughput systems, large datasets, or millions of requestsStrong communication skills and collaborative working styleComfortable operating in fast-paced startup environmentsDemonstrated obsession/mastery outside of work requiring long-term deliberate practice and disciplinePreferred Visa StatusUS Citizenship or Permanent Residency strongly preferredH-1B transfers consideredTech StackFrontendReactNext.jsTailwind CSSTypeScriptBackend & InfrastructurePythonFastAPISupabaseRedisAWS (Lambda, EC2, WebSockets, SIP)Voice AI & Real-Time SystemsLiveKitDeepgramCartesiaElevenLabsGeminiWebSocketsDevOps & ToolingCI/CD pipelinesPreferred QualificationsPrevious experience as a founding engineer at a YC-backed startupExperience building voice AI or conversational AI systemsStrong frontend product design and UI craftsmanshipExperience as a technical founder or startup operatorBackground at high-performance AI or infrastructure companiesCompensationCompensation & BenefitsBase Salary: $200,000 – $250,000 USDBenefits & PerksHealth insuranceGym membership reimbursement$500 desk and workspace stipendWork EnvironmentLocation: San Francisco, CaliforniaFully onsite with the founding teamOffice expansion underway as the company scales rapidlyHigh-intensity, high-ownership startup cultureWhy This Role Stands OutMassive Scale ChallengesThe platform is already operating at production scale with millions of real-time conversations each month, creating meaningful distributed systems and performance engineering challenges.Foundational OwnershipYou'll directly influence architecture, infrastructure, engineering standards, and product direction alongside the founding team.Elite Technical EnvironmentWork with experienced AI and infrastructure leaders from Microsoft, AWS, and top-tier startup ecosystems.Real Product & Customer ImpactYour systems directly shape the reliability and performance of AI agents deployed into real-world customer environments.High-Performance CultureThe company values craftsmanship, intensity, curiosity, and people who pursue mastery both inside and outside of engineering.