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

As part of our early talent program, Cartesia is hiring a Product Engineer Intern to ship high-impact, model-powered experiences across Cartesia’s surfaces—marketing site, onboarding flows, self-serve funnels, dashboards, docs, and APIs—in close collaboration with our GTM, model serving, research, and product teams.

You’ll work end-to-end across the stack to build, iterate on, and measure developer-first product experiences that drive activation, retention, and revenue. As a Cartesia intern, you’ll ship to production, own meaningful pieces of the product, and see your work directly impact Cartesia’s growth.

Your Impact

• Ship developer-first growth surfaces by combining user insights, data, and first-principles thinking.

• Bring Cartesia’s latest models to market by rapidly building high-performance interfaces and flows that help users discover, evaluate, and adopt them.

• Instrument and analyze key metrics (e.g., sign-up → first call, time-to-first-production-use, feature adoption) and iterate based on real user behavior.

• Communicate publicly about your work via Cartesia’s official channels as well as your own profiles.

• Collaborate cross-functionally with GTM, model serving, research, and product to craft surfaces that grow Cartesia and multiply our work.

• Help identify and reduce friction across the user journey—from first touch on the website to successful integration in production.

What You Bring

• Currently pursuing a degree in Computer Science, Engineering, or a related field, with at least one previous internship or substantial project experience in software development.

• Proficient in TypeScript, with experience building modern web applications using React or a similar framework.

• Comfortable working across the stack; some backend experience in Python or Go with a focus on APIs.

• Evidence of shipping and iterating on a user-facing product in a fast-moving environment (internships, side projects, hackathons, open-source, or startup experience).

• Deep intuition for what makes a great developer experience—clear docs, intuitive APIs, and fast, reliable interfaces.

• Curiosity about product metrics and experimentation; you’re excited to use data and user feedback to guide what you build.

• You’re a little unhinged.

Nice-to-Haves

• Experience building or instrumenting growth surfaces such as sign-up flows, pricing pages, dashboards, or docs.

• Familiarity with analytics and experimentation concepts (e.g., event tracking, A/B testing, funnels).

• Experience building voice agents or voice-enabled applications.

• Active online presence on X/Twitter, LinkedIn, or a personal blog showcasing projects, writing, or developer-focused work.

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.