Product Engineer - Web Platform

PassiveLogic•Holladay, UT

5d•Hybrid

About The Position

You'll build the applications that make autonomous building systems legible to humans. PassiveLogic's platform enables buildings to reason about their own operation using physics-based digital twins. The software you build is how users construct those twins, simulate building behavior, and interact with deployed autonomous systems. This isn't dashboard work—it's spatial, interactive, and often real-time. You'll render building models, visualize system behavior, and design interfaces that make complexity navigable rather than hidden. Our architectural philosophy rejects black-box AI. Users should understand what the system is doing and why. That constraint shapes everything about how we build interfaces—it demands clarity, not just functionality. What You'll Build Applications for constructing physics-based models. Users describe buildings and their mechanical systems through our tools. You'll build interfaces for creating, editing, and validating these models—work that combines structured data editing, spatial visualization, and domain-specific interaction patterns. Simulation and visualization tools. Before deploying autonomous control, users simulate building behavior. You'll build the interfaces that display simulation results, highlight anomalies, and help users develop intuition about how their buildings will perform. Operational interfaces for deployed systems. Once buildings are running autonomously, operators need to monitor, understand, and occasionally override system behavior. You'll build interfaces that surface the right information at the right moment without overwhelming users with data they don't need. Real-time collaborative features. Our applications are local-first—designed to work offline and synchronize when connected. You'll work with distributed data patterns (conflict resolution, optimistic updates) that most front-end roles never encounter. Our stack is TypeScript and Angular, with significant use of reactive programming patterns. We render building models and system schematics using WebGL and SVG—if you have graphics programming experience, you'll use it; if you don't, you'll develop it. The platform architecture is evolving toward Swift compiled to WebAssembly for core logic, with TypeScript at the application layer. You won't own that integration boundary (that's framework-level work), but you'll build on top of it and provide feedback that shapes how it develops. Understanding how to work effectively with that architecture—consuming reactive state from WASM modules, working within the patterns the framework provides—will be part of the role. We use a graph-based data model called Quantum for describing autonomous system digital twins, synchronized via a real-time protocol called DataSync. You'll learn these systems; prior familiarity isn't expected.

Requirements

Strong TypeScript and JavaScript fundamentals. You've built substantial applications in TypeScript, understand the type system deeply, and write code that other engineers can read and maintain.
Experience with modern front-end frameworks. Angular, React, Vue, Svelte—the specific framework matters less than understanding the underlying patterns: component architecture, state management, reactive dataflow, change detection. You should be able to reason about why frameworks make the tradeoffs they do.
Comfort with complexity. The applications we build aren't simple CRUD interfaces. You're energized rather than overwhelmed by domains with many interacting concepts. You can hold a mental model of a complex system and build interfaces that help users develop their own.
Visual and spatial thinking. Much of our UI is graphical—building schematics, system diagrams, data visualization. You don't need to be a designer, but you should be comfortable reasoning about spatial relationships, visual hierarchy, and interaction in two (and sometimes three) dimensions.
Attention to craft. You care about the details that separate adequate interfaces from excellent ones—animation timing, interaction feedback, edge case handling, performance under load. You notice when something feels slightly off and you fix it.
Experience level. Typically 4+ years building front-end applications, with at least some of that time on complex, data-rich interfaces. We're looking for engineers who've moved past the "making it work" phase into the "making it right" phase.

Nice To Haves

Graphics programming—WebGL, Three.js, D3, SVG manipulation. We do a lot of this.
Real-time data visualization or applications with live-updating state.
Local-first or offline-capable application architecture.
Domain experience in building systems, energy, IoT, or industrial software. (Helpful for intuition, but we'll teach the domain.)
Experience consuming platform APIs or working within opinionated framework architectures.