ProductEngineer

Job title: Product Engineer Location: London; full in-office working as default Start date: ASAP Reports to: Head of Engineering Compensation: BASE : £70,000 - £90,000 EQUITY : £70,000 - £90,000 ___________________________________________________________________________ COSINE AT A GLANCE At Cosine, we’re building autonomous AI engineers that plan, write, and ship code inside real development workflows. Cosine is designed for on-premise and virtual private cloud (VPC) deployments, including fully air-gapped environments. We build our agent tooling entirely in-house and post-train open-source models to deliver reliable, enterprise-grade coding performance in security-critical settings. In 2024, Cosine achieved a 72% score on OpenAI’s SWE-Lancer benchmark, placing us among the strongest real-world software-engineering AI systems evaluated. YC-backed and well-funded, Cosine was founded by experienced operators focused on building dependable, production-grade AI. This role is based in our Hoxton office, five days a week, because close collaboration, fast feedback, and shared context matter for the problems we’re solving. ___________________________________________________________________________ THE ROLE 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