Principal Product Engineer, Frontend

Why Flux Flux is taking the hard out of hardware, by developing the first AI Hardware Engineer. Our goal is to democratize the ability to create bleeding edge hardware, and revolutionize how electronics are designed and built around the world. The Role As a Principal Product Engineer, Frontend, you will set technical direction for the Flux web application. This is a systems-level role. You will shape architecture, performance strategy, state management patterns, and interaction models across a highly interactive, real-time, AI-augmented editor. You will operate as a force multiplier: raising engineering standards, mentoring senior engineers, driving cross-functional technical decisions, and ensuring the frontend scales with both product ambition and user complexity. You are expected to independently identify ambiguous, high-leverage problems and drive them to durable solutions. What You'll Own Define and evolve the frontend architecture of a large-scale, real-time browser-based engineering tool. Establish scalable patterns for state management, data synchronization, and multi-pane editing systems. Lead performance strategy for large and complex hardware projects. Design and review systems that integrate AI-powered workflows deeply into the UI. Drive standards for code quality, observability, and maintainability. Partner with backend and infrastructure engineers on API design and cross-system boundaries. Mentor senior engineers and raise the technical bar across the organization. Contribute to product strategy where technical constraints and opportunities shape direction. Required Qualifications Strong command of modern React and TypeScript in sizable production codebases. Experience shipping and iterating on complex, interactive web applications (e.g., design tools, visual editors, multi-pane interfaces). Experience building responsive UIs on top of asynchronous or computation-heavy backend systems. Strong product judgment and experience collaborating closely with design and product. Experience with browser performance profiling and debugging. Comfortable working across the stack to integrate APIs and make small backend changes. Experience in startup or high-ownership environments. Based in the San Francisco Bay Area or willing to relocate. Preferred Qualifications Experience with WebAssembly, WebWorkers, or client-side parallelization strategies. Experience designing AI-native product experiences. Contributions to widely used open source frontend or developer tooling. Prior exposure to CAD, ECAD, or other professional-grade design tools. Profile Systems thinker – You see around corners and design for long-term scalability. Technical leader – Others rely on your judgment for architectural decisions. Product-minded – You understand tradeoffs between velocity, usability, and technical rigor. Ambiguity-native – You define the map where none exists. Standards-setter – You elevate the people and systems around you. #J-18808-Ljbffr Flux