Founding Full Stack Engineer (Frontend + UX Focus) (Sonoma)HartleyCo • Sonoma, CA, United States

Founding Full Stack Engineer (Frontend + UX Focus) (Sonoma)

HartleyCo • Sonoma, CA, United States

[job_card.variable_days_ago]

[job_preview.job_type]

[job_card.full_time]

[job_card.job_description]

Founding Full Stack Engineer (Frontend + UX Focus)

Location : San Francisco (on-site)

Were helping a YC-backed, seed-stage startup hire a Founding Engineer who can take full ownership of the products look, feel, and overall experience. The company builds the simulation and evaluation layer for voice and text AI agents, used by both fast-growing startups and large enterprises.

This role is full stack, but the centre of gravity is very much the frontend. Youll be the person who makes a complex AI platform feel simple, fast, and genuinely enjoyable to use.

What Youll Own

End-to-end ownership of core UI : dashboards, debugging tools, evaluation workflows.
Turning rough ideas into product : sketching, prototyping and shipping quickly.
Driving UX quality across the product : layout, interaction, states, polish.
Building intuitive interfaces over real-time systems, large datasets, and AI outputs.
Dipping into the backend (Python / FastAPI, Supabase, AWS) to unblock yourself and shape APIs.

What Theyre Looking For

Strong front end engineering with sharp product taste.

Someone who cares about clean UI, clear UX flows, and fast interactions.

Ability to work full stack when needed, but happiest owning the product surface.

Comfortable working on-site with founders, shipping quickly, and iterating with customers.

Opinionated about design details and code quality.

Nice-to-Haves

Experience with React, TypeScript, Next.js, Tailwind.

Exposure to AI / voice tooling a bonus, not required.

Prior early-stage or YC / VC-backed startup experience.

Examples of beautiful or highly polished UI youve built.

If you want to define the visual and interactive identity of a high-velocity AI product and sit at the heart of a tiny founding team, this is the one.

[job_alerts.create_a_job]

Founding Engineer • Sonoma, CA, United States

[internal_linking.related_jobs]

Founding Product Engineer (Sonoma)

Brahma Consulting Group • Sonoma, CA, US

[job_card.part_time]

A Product Engineer in this role will focus on building and scaling a high-quality AI agent product with strong UX, fullstack development, and close user collaboration, and should bring 2+ years of ...[show_more]

[last_updated.last_updated_variable_hours] • [promoted] • [new]

Associate Development Engineer (4758C) - EECS

InsideHigherEd • Berkeley, California, United States

[job_card.full_time]

Associate Development Engineer (4758C) - EECS.At the University of California, Berkeley, we are dedicated to fostering a community where everyone feels welcome and can thrive.Our culture of opennes...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Founding Engineer (Sonoma)

trygravity.ai • Sonoma, CA, US

[job_card.part_time]

Please read in full : As a founding engineer, youll work across our entire stack to build and scale our contextual advertising network for AI tools. Youll have significant influence over technical di...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Forward Deployed Engineer (Sonoma)

Rise Technical • Sonoma, CA, US

[job_card.part_time]

Forward Deployed Engineer (AI Infrastructure).San Francisco, CA Onsite (6 days / week).Are you an engineer who loves solving complex, real-world problems directly with customers? Do you want to work...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

RN - Med Surg in Saint Helena, California - $1,844 / week

Vetted Health • Saint Helena, CA, US

[job_card.full_time]

Vetted is seeking a RN - Med Surg for a travel job in Saint Helena, California.The job was posted 20 days ago.The assignment starts on ASAP and is 13 weeks long with 13 hour shifts 3 days a week.Yo...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Urologist - St. Helena, CA

Adventist Health • St. Helena, US

[job_card.full_time]

This is an excellent opportunity to join our collegial and highly trained providers.The ideal candidate will be experienced as well as robot trained however, newly trained providers will still be c...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Full Stack Engineer (Sonoma)

BioTalent • Sonoma, CA, US

[job_card.part_time]

Join a fast-growing HealthTech company building an.This is a rare opportunity to contribute to technology that directly improves care outcomes and transforms how health plans and providers make dec...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Founding Engineer - Applied AI (Sonoma)

Strativ Group • Sonoma, CA, US

[job_card.part_time]

Founding Engineer - Applied AI.AI startup tackling a $100bn+ per year inefficiency in the physical world.Fresh off an 8 oversubscribed Seed round - with investors including Palantir and OpenAI - th...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Frontend Engineer

UMATR • Sonoma, California, United States

[job_card.full_time]

UMATR are supporting an early-stage AI startup on a mission to help growing organisations stay aligned and efficient as they scale. Our product acts as an intelligent teammate that understands a com...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Software Engineer for AI Startup (Sonoma)

Xcede • Sonoma, CA, US

[job_card.part_time]

A cutting edge AI startup based in San Francisco is looking for a founding engineer to own backend of their code generation platform. Software should be beautiful, and this firm aims to provide gene...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Travel MRI Tech - $2600 / Week

Uniti Med • Saint Helena, CA, US

[job_card.full_time]

Uniti Med is seeking an experienced MRI Tech for an exciting Travel Allied job in Saint Helena, CA.Shift : Inquire Start Date : ASAP Duration : 13 weeks Pay : $2600 / Week. Uniti Med provides career opp...[show_more]

[last_updated.last_updated_30] • [promoted]

Travel Behavioral Health Tech in St. Helena, CA

AlliedTravelCareers • St. Helena, CA, US

[job_card.full_time]

AlliedTravelCareers is working with Aequor to find a qualified Behavioral Health Tech in St.Registered Behavioral Tech (RBT). With Aequor, you can enjoy the freedom to advance your career and travel...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Senior Full-Stack Engineer (Multiple Opportunities) (Sonoma)

Harrison Clarke Ventures • Sonoma, CA, US

[job_card.part_time]

As part of Harrison Clarke Ventures mission to help exceptional founders scale from Seed through Series B, were looking to connect with software engineers who love building real products and taking...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Travel Surgical Tech in St. Helena, CA

AlliedTravelCareers • St. Helena, CA, US

[job_card.full_time]

AlliedTravelCareers is working with Aequor to find a qualified Surg Tech in St.With Aequor, you can enjoy the freedom to advance your career and travel the country, all while earning and learning.L...[show_more]

[last_updated.last_updated_30] • [promoted]

Mission Operations Ground Systems and Software Engineer (7115C), Space Sciences Laboratory - 82831

InsideHigherEd • Berkeley, California, United States

[job_card.full_time]

Mission Operations Ground Systems and Software Engineer (7115C), Space Sciences Laboratory - 82831.At the University of California, Berkeley, we are dedicated to fostering a community where everyon...[show_more]

[last_updated.last_updated_variable_days] • [promoted]

Staff Software Platform EngineerSoftware Engineering • Berkeley, CA; Somerville, MA; Weirton, WV • Full time • On-site

Form Energy • Berkeley, CA, United States

[job_card.full_time]

Are you ready to build America's energy future? Form Energy is an American manufacturing and energy technology company.We're revolutionizing energy storage with cost-effective, multi-day technology...[show_more]

[last_updated.last_updated_30] • [promoted]