Founding Engineer

Jackandjillai — United States · Posted ~2 days ago

Lead Full-time Onsite Visa History ✓ $170K-$200K + Equity

Skills

Full-Stack Development Distributed Systems TypeScript Next.js Mastra AWS

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Summary

We are a fast-growing, well-backed startup building autonomous AI operating systems for the commercial lending market. As our first Founding Engineer, you will architect and ship frontier AI agents that automate complex loan lifecycles, owning the product end-to-end. You will build core infrastructure using TypeScript, Next.js, and AWS, and deploy code directly on client systems. The ideal candidate has a strong background in full-stack and distributed systems engineering, a deep curiosity for AI agentic architectures, and a founding-engineer mindset that thrives on ownership and shipping fast. This role is onsite and requires travel to major financial institutions to iterate based on direct feedback.

Highlights

High-growth environment backed by top-tier investors with a direct path to seven-figure ARR. Enjoy a high-trust, low-overhead culture that prioritizes physical health and wellbeing, featuring no standups and fully expensed meals. The role offers competitive compensation plus equity and involves working on cutting-edge agentic architecture.

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 Founding Engineer Salary $170k-$200k + Equity Company Description Proximitty is a YC W26-backed fintech building autonomous AI operating systems for the $3T commercial lending market. Founded by veterans from McKinsey and Bloomberg, the company is backed by CRV and angels from Stripe and OpenAI, already tracking toward seven-figure ARR by automating legacy banking workflows for major US financial institutions. Job Description As the first Founding Engineer at Proximitty, you will architect and ship frontier AI agents that automate complex commercial loan lifecycles. You’ll own the product end-to-end, from document ingestion to real-time credit decisioning. This role involves working directly with founders and banking clients to deploy autonomous infrastructure in high-stakes, regulated environments. Location San Francisco, USA Why this role is remarkable Work on frontier agentic architecture involving long-horizon reasoning and self-healing systems that solve real-world problems in a $3 trillion market.Join a high-traction team backed by top-tier investors like Y Combinator and CRV, with a direct path to seven-figure ARR.Enjoy a high-trust, low-overhead culture with no standups, fully expensed meals, and a culture that prioritizes physical health and wellbeing. What You Will Do Build and own the core infrastructure for autonomous lending agents using TypeScript, Next.js, and Mastra.Deploy code live on client systems by flying to major banks and iterating based on direct feedback from credit officers.Create self-evolving agents and evaluation frameworks that ensure reliable performance in high-stakes, regulated financial environments. The ideal candidate Strong background in full-stack and distributed systems engineering, specifically using TypeScript and AWS for production applications.Deep curiosity for frontier AI agentic architectures and the ability to build reliable "computer-use" agents for brittle legacy systems.A founding-engineer mindset that thrives on ownership, customer empathy, and shipping fast without over-engineering or premature optimization. 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. How does this work? Jack's an AI agent for job searching and career coaching. He works for you.Jill is the AI recruiter working for the company. She recruits from Jack's network.If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives. 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.