Software Engineer, Agent Harness

Cartesia
San Francisco
Workplace: OnsiteFull timeUSD 180,000 - 250,000 annuallyFunction: Software EngineeringExperience: 3+ yearsSkills: ["Go","Python","Kubernetes","Docker","NATS","GRPC","OpenTelemetry","WebRTC","RTP","SIP","Low-latency audio"]

Join Cartesia to build the backend platform behind Line, a real-time voice agents product. Own distributed backend systems (Go API with Python workers), optimize latency and reliability, and shape the developer experience. Work end-to-end from spec to production, making architectural tradeoffs and defining APIs, observability, and evaluations for engineers building on Cartesia.

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FursaFursa
Cartesia
Cartesia
4 months ago

Software Engineer, Agent Harness

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Source: Company careers pageValidated by: Fursa AI
Last checked: 21 hours agoStatus: Live

Job Summary

Join Cartesia to build the backend platform behind Line, a real-time voice agents product. Own distributed backend systems (Go API with Python workers), optimize latency and reliability, and shape the developer experience. Work end-to-end from spec to production, making architectural tradeoffs and defining APIs, observability, and evaluations for engineers building on Cartesia.
Location: San Francisco
Workplace: Onsite
Employment Type: Full time · Permanent
Job Function: Software Engineering

Key Responsibilities

  • •Build and operate the distributed systems behind Cartesia's voice agents: load balancing servers, workers, and the realtime media pipelines that tie them together.
  • •Take projects from spec to production: design, build, ship, monitor, iterate.
  • •Make architectural calls that compound over time—latency budgets, reliability targets, scaling primitives—and clearly articulate the tradeoffs.
  • •Define the developer experience for engineers building on Cartesia: APIs, observability, and applied evaluations.
  • •Collaborate across teams to ensure backend systems meet performance and reliability goals.

Pay and Benefits

Salary: USD 180,000 - 250,000 annually
Equity and Bonus:Equity
Perks:Commuter BenefitsPaid LeaveMeal AllowanceEquity

Key Requirements

  • •3+ years building distributed backend systems in production, ideally at a high-growth startup.
  • •Strong product instincts for platform work; focus on latency, reliability, and developer experience.
Experience:3+ yearsAiVoice agentsCloudStartupSoftware
Skills:GoPythonKubernetesDockerNATSGRPCOpenTelemetryWebRTCRTPSIPLow-latency audio
Tech Stack:GoPythonKubernetesDockerNATSGRPCOpenTelemetryWebRTCSIPRTPSWE

Company Brief

Cartesia
Builds real-time multimodal and voice AI (Sonic) that generates expressive, low-latency speech for conversational agents and on-device experiences, serving developers and enterprises with APIs and SDKs.
Industry: AI & Machine Learning
Company Size: Small (11 to 50 employees)
Growth: Growth Stage Startup
Funding: Series A
Headquarters: San Francisco, United States
Founded: 2023
WebsiteLinkedInGlassdoor