Full Stack Engineer

Cross River • Fort Lee, NJ

5h • Onsite

About The Position

Cross River builds the infrastructure behind the world’s most innovative financial products, powering payments, cards, lending, and digital asset capabilities. Their technology and capital solutions move money safely, instantly, and inclusively, trusted by leading fintechs, enterprises, and disruptors globally. The company's mission is to build financial infrastructure that expands access and opportunity for all, guided by a culture of collaboration, curiosity, and purpose. Cross River has been recognized as one of American Banker’s Best Places to Work in Fintech. In this role, you will contribute to shaping the future of finance through innovation and integrity, specifically by leading the design, architecture, and enhancement of an LLM-based platform.

Requirements

• 4+ years of professional software development experience, with a proven track record of leading complex full-stack projects.
• Solid knowledge of React, modern JavaScript (ES6+), and state management patterns at scale.
• Proficiency in Python or Node.js, Express.js, and designing scalable Microservices architectures.
• Advanced experience with SQL and NoSQL databases, including performance tuning and schema design for high-load environments.
• Hands-on experience architecting on AWS (DynamoDB, S3, RDS, Lambda, and API Gateway).
• Deep understanding of TDD, CI/CD pipelines, and Agile/Scrum leadership.
• Ability to debug problems across distributed systems and optimize bottlenecks in real-time data flows.
• Great communicator with the ability to influence technical direction and manage stakeholder expectations.
• Professional experience or deep technical projects involving Large Language Models, Prompt Engineering, or RAG (Retrieval-Augmented Generation) workflows.

Nice To Haves

• Knowledge of Infrastructure as Code (Terraform/CDK).

Responsibilities

• Lead the design, architecture, and enhancement of our LLM-based platform, making high-level technical decisions regarding the python or Node.js and React ecosystem.
• Work closely with product managers and stakeholders to translate business vision into scalable technical requirements, leading cross-functional alignment between engineering teams.
• Architect applications for extreme speed and reliability, owning strategies for scaling to handle high traffic and complex real-time data processing.
• Design and oversee robust authentication and authorization frameworks (Identity Server, OAuth2, OpenID Connect), ensuring the platform meets enterprise-grade security standards for data protection.
• Set the standard for clean, maintainable, and testable code, leading rigorous code reviews and establishing "best practice" guidelines for the entire engineering team.
• Actively mentor junior and mid-level developers, driving a culture of technical growth, peer learning, and collaborative problem-solving.
• Stay at the bleeding edge of AI/LLM trends, evaluating and integrating emerging tools to enhance product intelligence.
• Lead the troubleshooting of complex, systemic issues across the stack and implement proactive monitoring to ensure high availability.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed
• Number of Employees: 501-1,000 employees