Product Engineer

Overview

Translate emerging model capabilities into concrete, user-facing features

A Product Engineer at Cosine works closely across research, engineering, product, and design to turn advanced AI capabilities into intuitive, reliable tools for developers.

You will be responsible for building and evolving Cosine’s user-facing product surfaces, including IDE extensions or dedicated apps and web applications that expose the power of our models through well-designed workflows and interfaces. Your work sits at the intersection of product, platform, and research, translating emerging model capabilities into concrete experiences developers can use every day.

We focus on rapid product iteration without compromising quality. This means building systems that are performant, observable, and robust, while remaining flexible enough to evolve alongside fast-moving research and user needs. You will help define how developers interact with Cosine, from first use through advanced, production-grade workflows.

Deliver a scalable, high-quality Cosine product experience by building IDE and web application interfaces and integrations that expose the power of our models in intuitive, reliable ways.

• Build end-user products (editor extensions and web applications and platform capabilities) that integrate with the Cosine platform APIs
• Enable developers to use advanced language models to augment their workflows and problem-solving capabilities
• Collaborate closely with research to explore and validate new product experiences and capabilities
• Translate emerging model capabilities into concrete, user-facing features
• Maintain a high bar for performance, reliability, and usability across platforms
• Be opinionated about and bring your own ideas to the table; we’re building for engineers, and as an engineer you have a say in what you want to use

• Experience building reactive, highly interactive applications (React, Svelte, Vue)
• Experience with CLI application development or local software development is a plus

• Comfortable with backend development
• Experience designing and consuming REST APIs

• Experience working with developer tooling
• Familiarity with CI/CD pipelines
• Experience with containerization

• Strong experience with Type Script and modern frontend frameworks
• Knowledge of Node.js, Python, and Go is a plus

• Git, Docker, Webpack, npm
• Monitoring and alerting tools (e.g. Grafana, Datadog)
• Feature flagging systems

• Have 5+ years of experience building production-grade software, with a strong emphasis on user-facing developer tools
• Have shipped and maintained complex frontend or full-stack applications used by technical users
• Are comfortable building highly interactive web or IDE-based experiences using modern frameworks (e.g. React, Type Script)
• Have experience designing and consuming APIs, and understand how frontend and backend systems evolve together
• Enjoy working close to the product surface, translating ambiguous ideas and model capabilities into intuitive developer workflows
• Care deeply about developer experience, performance, and reliability—not just functionality
• Are comfortable iterating quickly, running experiments, and refining products based on real user feedback
• Can operate effectively in a fast-moving environment with evolving priorities and incomplete information

We value diverse backgrounds, perspectives, and ways of thinking, and we’re committed to creating an inclusive and respectful workplace. We encourage applications from anyone who meets the role requirements, even if you don’t meet every single qualification. If you need reasonable adjustments at any stage of the hiring process, we’re happy to discuss them.

We’re an in-office team, five days a week, by design. We believe the work we’re doing benefits from being together, collaborating closely, and building shared context.

• Competitive salary, benchmarked to the market
• Equity / share options,…