Senior Frontend Engineer

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.

About the role

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.

Responsibilities

• Own the end-to-end experience Virtual Bid Assistants use to do their best work, from onboarding through daily workflow
• Design interaction patterns that surface what the AI is doing and keep skilled estimators in control
• Build responsive, performant interfaces using HTMX, Flask templates, and modern CSS/JS, and lead the external migration to React
• Partner closely with the designer and backend engineers to turn complex estimating workflows into something that feels simple
• Ensure performance, accessibility, and polish—because details close deals

Requirements

• 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
• AEC, glazing, or construction industry exposure
• Veteran or prior-service background (the founder is a Marine Corps Ground Intelligence Officer)

Location & Employment

Locations: New York City, NY | Washington, D.C., DC | Philadelphia, PA (Hybrid, Philadelphia HQ)

Employment: Full-time, Senior (5+ years experience)

Equity: Competitive equity, more generous as an early hire

Visa & work authorization: H-1B sponsorship available (H-1B transfer / F-1 OPT)