Senior Founding Engineer | San Francisco, CA | Avg $200K-$250K

Job Description Senior Founding Engineer | San Francisco, CA | Avg $200K–$250KRole OverviewA rapidly scaling AI technology company is seeking a Senior Founding Engineer to help architect and scale the infrastructure powering conversational AI evaluation, observability, and simulation systems handling millions of calls per month.This is a highly technical, architecture-heavy role focused on building resilient, scalable systems across the full stack. The company is looking for engineers who move quickly, think deeply about systems design, and care about building high-performance infrastructure that operates reliably at production scale.This role is ideal for experienced engineers who thrive in fast-moving startup environments, enjoy solving complex systems problems, and want direct influence over product architecture and engineering culture.About the CompanyThe company builds simulation, evaluation, and observability systems for conversational AI agents across voice and multimodal experiences. Founded by former AI engineers from Microsoft and AWS, the platform helps organizations validate and improve AI agent performance before deployment into real-world environments.Backed by Y Combinator, Floodgate, and PeakXV, the company has experienced rapid growth and now supports millions of AI-powered conversations per month for enterprise customers including major technology and Fortune 500 organizations.Key ResponsibilitiesSystems Architecture & ScalabilityArchitect and develop scalable systems supporting conversational AI evaluation and simulationDesign resilient infrastructure capable of handling millions of real-time interactionsOptimize backend systems, database performance, and frontend responsivenessReduce system bottlenecks across distributed services and infrastructure layersDesign systems prioritizing reliability, scalability, and operational efficiencyFull-Stack EngineeringBuild and maintain frontend and backend systems across the platformDevelop APIs, real-time systems, and infrastructure servicesImprove frontend dashboard performance and user experienceSupport CI/CD pipelines and production deployment systemsContribute to architectural decisions and technical directionAI & Conversational SystemsDevelop pipelines and systems that analyze conversational AI performanceDetect system failures, performance issues, and reliability gapsSupport voice AI and multimodal infrastructure initiativesBuild observability and evaluation tooling for AI agentsWork directly with customers on implementation and deployment effortsEngineering Leadership & StandardsEstablish strong engineering practices around architecture, code review, and system qualitySupport scalable engineering workflows within a fast-growing environmentCollaborate directly with founders and leadership teamsContribute to technical strategy and long-term infrastructure planningRequirementsMinimum 6 years of full-stack engineering experienceDeep proficiency in:TypeScriptPythonSQLAWSStrong systems architecture and scalability experienceExperience building and optimizing large-scale production systemsStrong communication and collaboration skillsComfortable working onsite within fast-paced startup environmentsAbility to move quickly while maintaining engineering quality standardsTech StackFrontend:ReactTailwindTypeScriptNextJSBackend:PythonFastAPISupabaseRedisAWS (Lambda, EC2, WebSockets, SIP)Voice AI & Infrastructure:LiveKitDeepgramCartesiaElevenLabsGeminiCI/CD pipelinesPreferred QualificationsFounding engineer or YC startup experienceVoice AI or conversational AI systems experienceExperience building polished frontend productsTechnical founder or VC-backed startup backgroundExperience within high-performance AI engineering environmentsStrong ownership mentality and systems thinkingCompensation & BenefitsAvg Base Salary: $200,000–$250,000Health InsuranceGym Membership Reimbursement$500 Workspace Setup StipendHigh ownership and direct impact opportunityFast-moving engineering culture with strong growth trajectoryInterview ProcessIntro Call with FounderTake-Home AssignmentTechnical InterviewOnsite Work TrialFinal OfferWork EnvironmentOnsite in San Francisco, CACollaborative startup environmentDirect access to founders and leadershipHigh-growth AI infrastructure companyExpanding engineering organizationIdeal CandidateHighly technical full-stack engineer with strong architecture depthComfortable operating in high-scale production environmentsStrong systems thinker and problem solverFast-moving, execution-oriented engineerLow ego with strong communication skillsPassionate about mastering technical and personal challengesExcited about building infrastructure powering the future of conversational AI