About Cartesia Our mission is to build the next generation of AI: ubiquitous, interactive intelligence that runs wherever you are. Today, not even the best models can continuously process and reason over a year-long stream of audio, video and text—1B text tokens, 10B audio tokens and 1T video tokens—let alone do this on-device.

We're pioneering the model architectures that will make this possible. Our founding team met as PhDs at the Stanford AI Lab, where we invented State Space Models or SSMs, a new primitive for training efficient, large-scale foundation models. Our team combines deep expertise in model innovation and systems engineering paired with a design-minded product engineering team to build and ship cutting edge models and experiences.

We're funded by leading investors at Index Ventures and Lightspeed Venture Partners, along with Factory, Conviction, A Star, General Catalyst, SV Angel, Databricks and others. We're fortunate to have the support of many amazing advisors, and 90+ angels across many industries, including the world's foremost experts in AI.

About The Role Cartesia is hiring a Software Engineer, Product to build and scale the platform infrastructure that powers Cartesia's voice AI products. You'll code composable platform components that accelerate feature delivery across our API and conversational AI systems.

Your Impact

• Build and scale product platform components to support Cartesia's growth.
• Own critical product infrastructure end-to-end, such as realtime infra.
• Work alongside product teams to identify shared needs and build platform primitives that multiply their velocity.

What You Bring

• 3+ years of experience as a backend or platform engineer building scalable systems.
• You think in terms of customer outcomes, not just technical requirements.
• Enjoy full ownership of your work, and effectively navigate ambiguous problems to deliver results.
• Strong judgment on when to move fast and when to invest in scalability.
• Comfort across our stack: TypeScript on the frontend, Python + Go on the backend. You don't need to be an expert in all three, but you're not afraid of any of them.

Nice-to-Haves

• Each of these is a plus, but not required to qualify for the role.

• Experience with PostgreSQL, Redis, NATS, or similar data and messaging systems at scale.

• Familiarity with real-time streaming systems, or WebRTC.

• Background in observability infrastructure (Datadog, Prometheus, OpenTelemetry) and building internal tooling for debugging production systems.

What We Offer 🍽 Lunch, dinner and snacks at the office.

🏥 Fully covered medical, dental, and vision insurance for employees.

🏦 401(k).

✈️ Relocation and immigration support.

🦖 Your own personal Yoshi.

Our Culture 🏢 We’re an in-person team based out of San Francisco. We love being in the office, hanging out together, and learning from each other every day.

🚢 We ship fast. All of our work is novel and cutting edge, and execution speed is paramount. We have a high bar, and we don’t sacrifice quality or design along the way.

🤝 We support each other. We have an open & inclusive culture that’s focused on giving everyone the resources they need to succeed.