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AI-Native Founding Engineer at Fancysauce Inc.

ID: 9099

Type: Full-time

Category: Others

Company Name: Jack & Jill

Location: California - California - United States

Education Level: Senior (5-10 years)

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Job Description

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers.

She will pick the best candidates from Jack's network

The next step is to speak to Jack.

Job Title: AI-Native Founding Engineer

Company Description: Fancysauce Inc. - AI-native load balancer for enterprise cost management

Job Description:
Join Fancysauce as our second engineer and partner with a proven founding team of Harvard grads and Apple alumni. You will own core platform verticals end-to-end, building agentic recipes that help companies optimize AI stacks. This high-autonomy role requires shipping fast in an AI-native environment to prevent company-compounding AI bills.

Location: San Francisco, USA

Why this role is remarkable:

  • Exceptional founding team with a history of success; the CEO previously scaled revenue to $100M+ with four successful exits, including Retain.ai ($30M raised).

  • Backed by tier-A investors including Afore Capital and strategic angels from industry leaders like OpenAI, Gemini, and Baseten.

  • Rare opportunity to join at the pre-seed stage as the second engineer, gaining massive equity and the ability to define agentic engineering principles from scratch.

What you will do:

  • Architect and deploy end-to-end product verticals, shipping high-quality code multiple times daily across the frontend, backend, and infrastructure.

  • Design and scale agentic engineering harnesses and observability tools that dynamically route model usage and optimize enterprise AI resources.

  • Act as a "manager of one" to define, plan, and execute technical roadmaps while collaborating directly with the CTO in a high-speed SF kitchen.

The ideal candidate:

  • 3-5+ years of experience in full-stack engineering roles, with deep fluency in TypeScript, React, SQL, and a strong comfort level with Python.

  • An AI-native builder who actively leverages agentic engineering principles and AI coding tools to multiply their own productivity and output quality.

  • Proactive problem-solver with a high tolerance for ambiguity, capable of digging into GCP logs one moment and architectural design the next.

Who are Jack & Jill?
Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.

Next steps
Step 1. Visit our website.
Step 2. Click 'Talk to Jack'.
Step 3. Talk to Jack so he can understand your experience and ambitions.
Step 4. Jack will make sure Jill (the AI agent working for the company) considers you for this role.
Step 5. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction.
Step 6. If not, Jack will find you excellent alternatives. All for free.

We never post fake jobs
This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network.
Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description.
We appreciate this can make them look a bit suspect, but there isn't much we can do about it.
Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.

Company Information

Company Name: Jack & Jill

Company Website: https://jackandjill.tech

Company Address: San Francisco, CA 94103, United States

Jack & Jill is a private technology product studio and software services company that positions itself as a full‑service partner for digital product design, engineering and platform delivery. The company offers end‑to‑end software development capabilities spanning product strategy and discovery, user experience (UX) and user interface (UI) design, mobile and web application engineering, cloud architecture and operations, and data & analytics. Jack & Jill typically works with early‑stage startups, scaleups and mid‑market enterprises to define product roadmaps, build minimum viable products (MVPs), and iterate toward production‑grade SaaS and consumer applications. Core business activities at Jack & Jill center on digital product development and technology consulting. The firm conducts product discovery workshops and user research to align feature priorities with measurable business outcomes, then translates those findings into interactive prototypes and design systems. Engineering teams deliver native and cross‑platform mobile applications (iOS/Android), responsive single‑page web applications, backend APIs, and integrations with third‑party services. Jack & Jill also provides cloud infrastructure design and DevOps/CI‑CD services to support scalable deployments on major cloud providers, and offers ongoing product support, performance monitoring and incident response services. In addition to application development, the company provides data‑focused services including analytics instrumentation, data pipeline implementation, dashboards and reporting, and basic machine learning model prototyping to help clients extract insights from product usage and customer behavior. The studio emphasizes pragmatic architecture choices and modular codebases to reduce technical debt and enable faster iteration cycles. Typical technical stacks used include modern frontend frameworks for web clients, cross‑platform or native frameworks for mobile, cloud‑native microservices patterns for server‑side components, and common relational and NoSQL datastore technologies for persistence. Jack & Jill positions its offerings around a product‑centric workflow: discovery and validation, design and prototyping, iterative development, deployment and operations, and continuous optimization informed by product analytics. Service engagements vary from short discovery and prototyping sprints to multi‑quarter engagements to build and operate production platforms. The company commonly supports clients through advisory services on product strategy, digital transformation initiatives, and technical due diligence for investments or M&A activity. Industries served by Jack & Jill are diverse and typically include consumer mobile apps, e‑commerce & retail platforms, marketplace businesses, digital health and wellness products, and B2B SaaS solutions for professional services and operations. The company highlights cross‑functional collaboration between designers, engineers and product managers as a distinguishing capability that enables rapid validation of ideas and time‑to‑market acceleration. This collaborative model is intended to help non‑technical founders and product owners translate customer needs into tangible software deliverables. On the product side, Jack & Jill’s deliverables commonly include clickable prototypes and design systems, production‑ready mobile and web applications, API and microservice implementations, and cloud configuration for scalability and resilience. The company frequently provides documentation and knowledge transfer to client internal teams, and can remain on retainer to deliver ongoing feature development, technical support and optimization. While Jack & Jill’s scale and organizational details may vary by market (it often operates as a boutique studio with small, cross‑disciplinary teams per client), the company’s public positioning emphasizes speed, quality engineering practices and a focus on measurable product outcomes such as user activation, retention, revenue conversion and operational efficiency. The firm typically advocates iterative delivery with frequent user feedback loops, automated testing, and continuous integration to minimize release risk. Jack & Jill’s commercial model spans fixed‑scope engagements for defined deliverables, time & materials for ongoing development needs, and longer‑term managed services or product‑as‑a‑service arrangements where the studio assumes responsibility for running parts of the client’s product stack. Pricing and engagement structures are tailored to client requirements, and the company commonly provides case studies and portfolio examples to illustrate domain experience and execution approach. Overall, Jack & Jill presents itself as a technology partner focused on turning product ideas into working, maintainable software systems with an emphasis on design quality, pragmatic engineering and operational readiness.
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