Principal Full Stack Software Engineer

About the role Skills: Python, React, TypeScript About JITX JITX is revolutionizing circuit board design by making it code-first. Instead of dragging components around in a GUI, engineers write code—or have AI write it for them—to define their circuit boards. We're a ~20-person startup building tools that bring software engineering practices to hardware design. The Role We're looking for a principal engineer who can drive technical direction for significant product areas and own them end-to-end. You'll work across our stack—from user management systems to our core design application—making architectural decisions that shape how electrical engineers interact with our product for years to come. As a principal engineer, you'll be expected to identify technical debt, propose solutions, and drive consensus around the right path forward. Your first major project will be reworking our user and license management system, which you'll architect and largely implement while coordinating with stakeholders across the company. As you ramp up and build context on our domain, you'll transition to working on critical core runtime components that power our circuit design engine. Beyond your individual contributions, you'll raise the bar for engineering across the team—through code reviews, technical mentorship, and establishing patterns that others can follow. What You'll Work On User Management Platform TypeScript/React frontend Python application server Database backend currently in PostgreSQL Integration with modern auth solutions (WorkOS or similar) Graphical User Interface Application Electron based React/TypeScript application Custom input handling and rendering (not traditional HTML elements) Advanced visualization using PixiJS, with potential migration to WebGL/Three.js Complex CSS/styling for polished UI/UX Application Runtime & Architecture Algorithm-heavy runtime with complex computational geometry problems User-facing Python API for programmatic circuit board design What We’re Looking For Must-haves: Extensive full stack experience with TypeScript/React and Python, with a track record of architectural decisions at scale Strong algorithmic problem-solving skills with understanding of complexity analysis, graph/tree data structures, and computational efficiency Ability to drive technical direction and follow through on architectural decisions across the stack Experience identifying technical debt, evaluating tradeoffs, and building consensus around solutions Self-directed work style with strong product sense and ability to unblock yourself and others Experience gathering requirements from stakeholders and translating them into technical solutions and system designs Track record of owning large, complex features from planning through production Ability to mentor and raise technical standards across a team through code reviews and establishing best practices Comfortable working with ambiguity in a startup environment Nice-to-haves: Experience with graphics/visualization libraries (PixiJS, Three.js, WebGL) Background in developer tools or technical products MongoDB and PostgreSQL experience, or other databases Auth/identity management systems (WorkOS, Auth0, etc.) Polyglot programming experience—comfortable across multiple languages and paradigms Interest in hardware, electronics, or CAD tools Who You Are You're a veteran software engineer who's worked across multiple environments and knows that early-stage startups offer the best combination of impact and interesting problems to solve. You have a nose for bottlenecks—you spot where things are getting stuck and jump in to help get features across the finish line. You're naturally curious about architecture, always tinkering to find proactive improvements that can ship quickly. You move fluidly across the codebase and the team, bringing speed without sacrificing quality. Your algorithmic problem-solving is strong and you don't shy away from maths and logic. You're comfortable reas