Company Overview Rex is a privately held ecosystem of entrepreneurial ventures led by Peter Rex, spanning real estate private equity, technology, insurance, and AI. We build businesses and investment platforms that generate both exceptional financial returns and meaningful societal impact. At the core of our strategy is investor engagement: attracting aligned capital partners who share our long-term vision. We are building the most compelling investor-facing ecosystem in the private markets. The role offers exposure to a uniquely diverse platform, combining institutional-quality real estate and high-growth tech ventures, all aligned under a singular mission-driven vision. About Us Our mission is to catalyze human flourishing through stewardship, serving people in all nations. We seek a transcendent impact, second to none, crossing geographies and making a permanent mark on history. We aim to uplift investors, foster flourishing families, create enduring trust, and contribute to a more beautiful world through our investments, products and services, and new ventures. Our investments are primarily in real estate, with additional allocations to tech, energy, and alternatives, employing a downside-protected, long-term approach to investing. We are grounded in timeless morals and seek to preserve and grow both investor capital and our own. The Opportunity Rex is seeking a Founding Product Engineer to build the core of its real estate ERP, an AI-first platform that becomes the single source of truth across the business. This role owns building two foundational products will underpin all financial, operational, and reporting workflows. This is not incremental work. This is defining how the system thinks and operates at scale. This role is anchored by three mandates: (1) build accounting systems that are uncompromisingly correct across tax, compliance, reporting, and auditability; (2) deliver a product experience operators trust and rely on daily; and (3) architect an AI-first system from the ground up, embedding intelligence into workflows and turning financial data into real-time, decision-grade insight. You will own this end-to-end, from architecture through execution, tightly integrated with the broader Rex tech ecosystem. The ideal candidate is an engineer by training who has grown into a product leader building systems people depend on. You have led products where correctness matters. You bring persistence, high standards, and judgment, the kind of builder you would trust with critical infrastructure. Early in your career, but already operating with ownership. You are AI-first in how you think and build. This is not for trend-chasers or resume builders. It is for serious builders who care about durability and truth in systems, and believe AI should strengthen those standards. Must deeply believe in what we are building. Must be missionary to the bone, fully aligned with the mission and relentless in pursuit of it. Fully remote. About the Role Rex is hiring a Founding Product Engineer to translate the vision of an AI-first real estate ERP into a durable, trusted system that becomes the single source of truth across the business. This platform will unify financial, operational, and reporting workflows. The mandate is clear: build systems that are exact in their correctness, trusted in daily use, and intelligent by design. This role owns outcomes across product, engineering, and architecture, ensuring speed, rigor, and precision in how the system is built and deployed. You will operate as the connective tissue between accounting, operations, and engineering, driving alignment between real-world workflows and system design while maintaining uncompromising standards for accuracy, auditability, and performance. You will architect and build an AI-first platform from the ground up, embedding intelligence into workflows and turning financial data into real-time, decision-grade insight. You will establish systems, product principles, and engineering discipline that convert complexity into clarity, balancing technical depth with product usability and ensuring the system scales with the business. This is a hands-on, high-impact role for a builder who has grown from engineering into product leadership, with the ability to own critical infrastructure end to end. It is a front-line seat for someone who wants to define how a business operates through software, not just ship features. Key Responsibilities - Own the end-to-end development of products that will produce/protect accurate information from a tax and accounting perspective - Architect system design to ensure accuracy across tax, compliance, reporting, and auditability requirements - Build and lead engineering efforts, writing code where needed and setting technical direction - Translate accounting and operational workflows into scalable, intuitive product experiences - Design and implement AI-first capabilities that embed intelligence into core workflows and reporting - Establish data models, system architecture, and integrations across the broader Rex tech ecosystem - Partner closely with accounting, finance, and operations teams to ensure real-world correctness and usability - Drive product roadmap, prioritization, and execution with a bias toward speed and quality - Ensure system reliability, performance, and scalability as usage and complexity grow - Implement best practices for code quality, testing, deployment, and security - Evaluate and integrate third-party tools, APIs, and infrastructure where appropriate - Continuously refine the system to improve usability, automation, and decision-making capabilities - Operate with full ownership and accountability for product outcomes and system integrity Ideal Candidate Profile - 5-8+ years of experience in software engineering, with progression into product leadership or technical product ownership roles - Strong engineering foundation with proficiency in modern programming languages such as TypeScript, Python, or similar - Experience building and shipping complex, data-intensive systems where correctness and reliability are critical - Background in fintech, accounting systems, ERP platforms, or infrastructure software strongly preferred - Familiarity with accounting principles, financial reporting, and compliance requirements, or demonstrated ability to learn quickly and operate with precision - Experience designing system architecture, data models, and scalable backend systems - Hands-on experience with modern frameworks and tools such as React, Node.js, Postgres, and cloud platforms like AWS or GCP - Familiarity with AI and LLM-based systems, including how to embed intelligence into workflows and products - Experience working with APIs, integrations, and distributed systems across multiple products - Strong product instincts with the ability to translate user needs into clean, effective system design - Demonstrated ability to operate with ownership in ambiguous, zero-to-one environments - High standards for code quality, system integrity, and user experience - Strong communication skills with the ability to work cross-functionally with technical and non-technical stakeholders - Builder mindset with a focus on durability, correctness, and long-term system value over short-term wins - High agency, persistence, and bias toward action in solving hard problems - Bachelor’s degree in computer science, engineering, or a related field preferred - Missionary mindset with full alignment to Rex’s mission and a disciplined, truth-seeking approach to building systems Rex Ecosystem-Wide Mission Catalyze Human Flourishing through our products and services and to elevate and further humanity in all our business dealings. Rex Values / Rex Culture - Customer Fanatic. We fanatically focus on customers, seeking to ever-deliver more value, and inventing and innovating on their behalf. - Product/Service Passion. Our business thrives or dies by products and services. - Ludicrous Speed. Our default pace is extremely fast. Time is precious, life is short, and moving fast is more fun and effective. - FAWOMO. We will find a way, or make one. - Loves Going to War. Prefers wartime to peacetime, always hungry to move forward, do more, and push growth. - Chutzpah. Nothing ventured, nothing gained. Fortune favors the bold. Duc in altum. - Fun. We should only do work, over the long run, that is fun, and work with fun people. Jokes and humor welcomed, PC stuff and uptight behavior prohibited. - Never-Lose-Money Approach. Protects the downside, using careful analysis before deploying significant resources, and ensuring cash is plentiful, never risking what others have and need for what they do not have and do not need. - Other-Centered. Idealist, desperate more than anything to leave an impact with their life by helping other people, seeing money as a means to serve. - Creative Cost Cutting Constantly. There is always a smarter way, always room to cut, always ways to do more with less. A cost advantage is a competitive edge. - Fewer, More Capable. Bias to as lean of a team as possible, with the highest competency, reducing communication and coordination, creating more effectiveness. - Underdogs. What we have done is nothing compared to what we are going to achieve now. We are fighting to be the best, clawing and biting up and forward, aiming to be the champs, be number one. Scrappy AF no matter how much we accomplish. We have never arrived in our minds. We are the underdogs always. - Other Attributes Valued. Point-blank forthrightness in conversation with teammates, brutally facing problems. Velvet glove with iron fist in human dealings. Shrewd as a serpent innocent as a dove. Hardcore work hustle. Invictus mentality. Swagger with humility. Quiet professionalism. Thrifty and not materialistic. Loves who they work with, loves what they do, and loves who we serve. Compensation & Benefits Base Salary: Commensurate with experience and market standards Opportunity for performance based bonus and/or equity in deals and funds Benefits: - Comprehensive health, dental, and vision insurance - 401(k) with company matching - Fully remote work environment