{"schemaVersion":"jobsearcher.job.v1","id":"7b175bcda6a2b3e0551e7a51","url":"https://jobsearcher.com/jobs/7b175bcda6a2b3e0551e7a51","canonicalUrl":"https://jobsearcher.com/jobs/7b175bcda6a2b3e0551e7a51","title":"Full-Stack Engineer","description":"About The CompanyWe build infrastructure for Agent Behavior Monitoring (ABM). While traditional observability focuseson logging exceptions and latency, ABM surfaces behavioral anomalies such as instruction drifts and contextretrieval loss in scaled production environments. Hundreds of teams building autonomous agents rely on our platform to understand how their systems are behaving post-deployment. The team has raised $30M+ across two rounds in the past five months.About the RoleWe're hiring a Full-Stack Engineer to own the product experiences and agent infrastructure thatmake the agent improvement loop legible and actionable for engineering teams. This is not a role where youimplement specs handed down: you will talk to customers, define what to build, build it, and iterate until it isgreat. The role spans from the data layer to the UI, including the agent swarm interfaces, verification platforms,and the SDK layer that lets developers summon our mid-development. About 30% of the role is customer-facing.What You'll OwnShape how our Agent runs large-scale parallel investigations across thousands of production traces, merging failure modes, tool errors, regressions, and drift signals into a single actionable answerBuild the platform for verifying agent changes: hosted simulated environments for stateful agent evals, trajectory replay against changed agents, and monitors for unintended behaviorDesign how engineers understand long traces, tool calls, decisions, and failures: making a thousand-step reasoning trajectory legible in minutesBuild the swarm UX so engineers can watch parallel investigations, redirect investigators that go down the wrong path, and consume findings without reading hundreds of reportsOwn the improvement loop: the workflows that turn production trajectories into datasets, judges, and regression checks so the path from found problem to verified fix feels like one motionBuild and maintain the SDK and terminal-first experience so agent development sessions can summon our agent as a subagent mid-developmentOwn platform infrastructure: workspaces, roles, permissions, billing, usage, and limits for teams running many agents across many environmentsRequirementsMust-HaveExperience building and scaling end-to-end production systems, from data layer to UIHands-on experience building with LLMs or agents, or demonstrable drive to get there fastComfort working directly with customers to understand their needs and solve real-world problems(approximately 30% of the role is customer-facing)Strong technical problem-solving ability in fast-changing, ambiguous environmentsExcellent communication skills: clear, direct, and persuasive across technical and non-technical audiencesBased in San Francisco or willing to relocate; 5 days per week in-personNice-to-HavePrior evals, observability, or agent behavior-monitoring product experienceStrong engineering pedigree from a solid product company (e.g. Roblox, Snapchat, Tesla); top-tier infra background (e.g. Databricks) is a bonusPrior forward-deployed or solutions engineering experiencePrior 0-to-1 startup experience as an early hireFounder background or strong founder-to-be signalComfort across the full stack with backend and infrastructure weightVisa Sponsorship: H-1B, O-1, OPTNB: We work in person in San Francisco. We're open to sponsoring truly exceptional candidates on a case-by-case basis, but our main scope will be candidates who don't require this.CompensationJunior level (3 years experience): $200KMid to senior level (3-7 years experience): up to $300KException: exceptional AI-savvy FDE leads can reach $400K on a case-by-case basis","company":"Ersilia","rawCompany":"ersilia","city":"Millbrae","state":"CA","isRemote":false,"isActive":false,"createdAt":"2026-10-08T13:36:34.792Z","occupations":[{"code":"15-1252.00","title":"Software Developers","slug":"software-developers"},{"code":"15-1299.08","title":"Computer Systems Engineers/Architects","slug":"computer-systems-engineers-architects"},{"code":"15-1254.00","title":"Web Developers","slug":"web-developers"}],"industries":[{"code":"541511","title":"Custom Computer Programming Services","slug":"custom-computer-programming-services"},{"code":"513210","title":"Software Publishers","slug":"software-publishers"},{"code":"541512","title":"Computer Systems Design Services","slug":"computer-systems-design-services"}],"jobPosting":{"@context":"https://schema.org","@type":"JobPosting","title":"Full-Stack Engineer","description":"About The CompanyWe build infrastructure for Agent Behavior Monitoring (ABM). While traditional observability focuseson logging exceptions and latency, ABM surfaces behavioral anomalies such as instruction drifts and contextretrieval loss in scaled production environments. Hundreds of teams building autonomous agents rely on our platform to understand how their systems are behaving post-deployment. The team has raised $30M+ across two rounds in the past five months.About the RoleWe're hiring a Full-Stack Engineer to own the product experiences and agent infrastructure thatmake the agent improvement loop legible and actionable for engineering teams. This is not a role where youimplement specs handed down: you will talk to customers, define what to build, build it, and iterate until it isgreat. The role spans from the data layer to the UI, including the agent swarm interfaces, verification platforms,and the SDK layer that lets developers summon our mid-development. About 30% of the role is customer-facing.What You'll OwnShape how our Agent runs large-scale parallel investigations across thousands of production traces, merging failure modes, tool errors, regressions, and drift signals into a single actionable answerBuild the platform for verifying agent changes: hosted simulated environments for stateful agent evals, trajectory replay against changed agents, and monitors for unintended behaviorDesign how engineers understand long traces, tool calls, decisions, and failures: making a thousand-step reasoning trajectory legible in minutesBuild the swarm UX so engineers can watch parallel investigations, redirect investigators that go down the wrong path, and consume findings without reading hundreds of reportsOwn the improvement loop: the workflows that turn production trajectories into datasets, judges, and regression checks so the path from found problem to verified fix feels like one motionBuild and maintain the SDK and terminal-first experience so agent development sessions can summon our agent as a subagent mid-developmentOwn platform infrastructure: workspaces, roles, permissions, billing, usage, and limits for teams running many agents across many environmentsRequirementsMust-HaveExperience building and scaling end-to-end production systems, from data layer to UIHands-on experience building with LLMs or agents, or demonstrable drive to get there fastComfort working directly with customers to understand their needs and solve real-world problems(approximately 30% of the role is customer-facing)Strong technical problem-solving ability in fast-changing, ambiguous environmentsExcellent communication skills: clear, direct, and persuasive across technical and non-technical audiencesBased in San Francisco or willing to relocate; 5 days per week in-personNice-to-HavePrior evals, observability, or agent behavior-monitoring product experienceStrong engineering pedigree from a solid product company (e.g. Roblox, Snapchat, Tesla); top-tier infra background (e.g. Databricks) is a bonusPrior forward-deployed or solutions engineering experiencePrior 0-to-1 startup experience as an early hireFounder background or strong founder-to-be signalComfort across the full stack with backend and infrastructure weightVisa Sponsorship: H-1B, O-1, OPTNB: We work in person in San Francisco. We're open to sponsoring truly exceptional candidates on a case-by-case basis, but our main scope will be candidates who don't require this.CompensationJunior level (3 years experience): $200KMid to senior level (3-7 years experience): up to $300KException: exceptional AI-savvy FDE leads can reach $400K on a case-by-case basis","datePosted":"2026-10-08T13:36:34.792Z","dateModified":"2026-10-08T13:36:34.792Z","hiringOrganization":{"@type":"Organization","name":"Ersilia","sameAs":"https://jobsearcher.com"},"jobLocation":{"@type":"Place","address":{"@type":"PostalAddress","addressLocality":"Millbrae","addressRegion":"CA","addressCountry":"US"}},"identifier":{"@type":"PropertyValue","name":"JobSearcher","value":"7b175bcda6a2b3e0551e7a51"},"url":"https://jobsearcher.com/jobs/7b175bcda6a2b3e0551e7a51"}}