Senior Frontend Engineer - React Migration & AI-native Interface

Who We're Looking FOR an AI-native, 0-to-1 frontend builder with strong browser fundamentals who can spearhead a migration from server-rendered HTMX to React and thrives owning features end to end in ambiguity.

You will own the interface where clients work with their Virtual Bid Assistants, from onboarding through daily workflow. Today, the product is built with a server-rendered HTMX and Flask approach: fast, lean, and tightly coupled to real product logic rather than a heavy single-page app. The team is splitting its internal and external portals: the current app becomes the internal tool (likely staying on HTMX, which is backend-friendly), while the external experience is being redesigned in React. A key part of this role is spearheading that migration.

The external redesign is also a shift in kind, not just stack: it is moving from a traditional software interface toward a human-plus-AI co-working workspace (think a Notion- or Cowork-style environment, but for glazing estimators) where users come in and actually finish the task, not just view data. An engineer who is excited about human-AI interaction and has opinions about how it should work will do especially well. This is an engineering role, not a design role; the team already has a designer, and this person owns the frontend build.

Details

Location: New York City, NY

• Washington, D.C., DC
• Philadelphia, PA
• Hybrid (Philadelphia HQ) Employment: Full-time Seniority: Senior (5+ years) Equity: Competitive equity, more generous as an early hire Delivery owner: Not specified Visa & work authorization: H-1B sponsorship available (H-1B transfer / F-1 OPT)
  
  
  

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Our client builds vertical AI for commercial glazing contractors, the teams that construct the glass facades of the world's most iconic buildings. Winning these high-stakes bids means estimators drowning in RFPs, addenda, and vendor quotes. Guthrie AI pairs every client with a Virtual Bid Assistant: a skilled human estimator powered by its proprietary platform, who pulls scope from RFPs, manages RFIs, and generates proposals at a speed no solo estimator could match. The company is around $2M ARR with a plan to 10x in the next 12 months. It is seed-stage, AI-native, backed by top VCs, and moving fast.

What You'll Own

The end-to-end experience Virtual Bid Assistants use to do their best work, from onboarding through daily workflow

Interaction patterns that surface what the AI is doing and keep skilled estimators in control

Responsive, performant interfaces built on HTMX, Flask templates, and modern CSS/JS, and spearheading the external move to React

Close partnership with the designer and backend engineers to turn complex estimating workflows into something that feels simple

Performance, accessibility, and polish, because details close deals

Your Background (Must-Have)

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5+ years building production, product-facing web applications

Strong HTML, CSS, and JavaScript fundamentals: you understand the browser, not just a framework

React proficiency, with the ability to spearhead a migration from server-rendered HTMX to React

A 0-to-1 track record: you thrive in ambiguity and own features end to end, shipping real product to real users fast

AI-native builder: deep, demonstrated experience using AI to build, ship, and accelerate work; you can take an ambiguous problem and ship a working solution

Able to interact effectively with a Python backend (not as a backend engineer, but fluent enough to be effective on the frontend)

Nice to have

HTMX or server-rendered / hypermedia experience, or genuine eagerness to work this way

Python and Flask comfort for full-stack feature work

Experience designing AI-first or agentic AI products, and an opinion on human-AI interaction

Experience simplifying complex workflows in a B2B setting

Growth from IC to team lead, or early-to-late-stage scaling experience (helpful, not required)

AEC, glazing, or construction industry exposure

Veteran or prior-service background (the founder is a Marine Corps Ground Intelligence Officer)

Interview process

1. Pending approval - candidate awaiting initial approval

2. Founder round - culture and vibe, non-technical

3. Technical round - with the CTO and the product designer

4. Final round

5. Offer extended

6. Hired