[Hiring] Founding Product Engineer @Rex

Role Description

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 that 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:

• Build accounting systems that are uncompromisingly correct across tax, compliance, reporting, and auditability.
• Deliver a product experience operators trust and rely on daily.
• 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. 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.

Qualifications

• 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.

Requirements

• 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.

Benefits

• Base Salary: Commensurate with experience and market standards.
• Opportunity for performance-based bonus and/or equity in deals and funds.
• Comprehensive health, dental, and vision insurance.
• 401(k) with company matching.
• Fully remote work environment.