Founding Engineer ($170k-$200k + Equity) at Proximitty

About the role

Proximitty is a YC W26 fintech startup developing autonomous AI operating systems for the commercial lending sector. As the first engineering hire, you will build and deploy agentic infrastructure to automate workflows for major financial institutions.

Key facts

What you'll do

• Architect and manage the full product lifecycle for autonomous lending agents, covering everything from document ingestion to credit decisioning.
• Develop and maintain core infrastructure using TypeScript, Next.js, and Mastra.
• Travel to client sites at major banks to deploy systems and refine code based on direct input from credit officers.
• Design self-evolving agents and evaluation frameworks capable of operating reliably within regulated financial environments.

Requirements

• Proven experience in full-stack and distributed systems engineering.
• Proficiency in TypeScript and AWS for production-grade applications.
• Ability to build reliable computer-use agents that interact with legacy systems.
• A founding-engineer mindset focused on speed, ownership, and direct customer interaction.

Skills & tools

• TypeScript
• Next.js
• Mastra
• AWS

Practical notes

• This role is backed by Y Combinator, CRV, and investors from Stripe and OpenAI.
• The company culture includes no standups and fully expensed meals.
• Jill, the AI recruiter, is managing this search and will facilitate introductions for candidates from Jack's network.