Founding Engineer (HCI focus)

Phosphor (Headquarters: NYC)

HCI Founding Engineer Frontend TypeScript ProseMirror Rich Text Sync Engine UI/UX Architecture Stealth Deeptech Senior Staff Wolfram Linear Front End Engineer Staff Engineer

Company Overview:
Phosphor enables the development of the built world (e.g. from real estate to energy projects) to be managed agentically by building programming languages and observability primitives (like version control) on top of a hypergraph. Our product is similar a combination of Linear and Wolfram, enabling advanced financial modeling, legal/regulatory analysis, and geospatial analysis. We are a stealth, venture-backed deeptech company aiming to bring agentic experiences and observability to new markets.

Role Description:
As a Founding Engineer with a focus on Human-Computer Interaction (HCI), you will be pivotal in shaping the user experience of our core product. You'll design and implement sophisticated front-end interfaces, focusing on rich-text editing capabilities, intuitive data interaction, and seamless collaboration features. This senior/staff level role involves significant architectural decisions regarding the front-end stack and the real-time synchronization engine required to support our agentic workflows.

Responsibilities:
* Lead the design and development of user-facing features using modern web technologies.
* Build and maintain complex rich-text editing experiences, likely leveraging libraries like ProseMirror.
* Architect and implement efficient data synchronization mechanisms between the front-end and our hypergraph backend.
* Collaborate closely with the team to define product requirements and user interaction paradigms.
* Champion best practices in front-end development, testing, and usability.

Technical Skills & Qualifications:
* Proven expertise in front-end development, particularly with TypeScript.
* Deep experience with rich-text editing libraries and frameworks (ProseMirror wizardry is a big plus).
* Strong understanding of HCI principles and designing complex user interfaces.
* Experience architecting and building scalable front-end applications.
* Familiarity with real-time collaboration patterns and synchronization techniques.
* Experience at a senior or staff engineering level.

Ideal Candidate:
You are passionate about building powerful, intuitive tools for end-users. You likely follow cutting-edge HCI research (e.g., Ink & Switch, UCSB HCI lab) and have strong opinions about crafting excellent user experiences. You thrive in a fast-paced startup environment and are excited by the challenge of building foundational technology.