Full Stack Engineer

Full Stack EngineerFort Lee, New Jersey, United StatesCross River builds the infrastructure behind the world's most innovative financial products. Our technology and capital solutions power payments, cards, lending, and digital asset capabilities that move money safely, instantly, and inclusively — trusted by leading fintechs, enterprises, and disruptors across the globe.Our mission is simple: to build the financial infrastructure that expands access and opportunity for all. Guided by a culture of collaboration, curiosity, and purpose, Cross River has been named one of American Banker's Best Places to Work in Fintech year after year. Whether you're designing code, solving regulatory puzzles, or developing strategy, you'll join a team where innovation and integrity drive everything we do — and where your work helps shape the future of finance.What We're Looking ForCross River Bank is seeking a Senior Full Stack Engineer who thrives at the intersection of intelligent systems and polished product experiences. You'll work across the entire stack from designing React interfaces that surface AI capabilities to engineers and end users, to building the Python and Node.js services that power our LLM-based Agentic platform. A key part of this role is hands-on experience with designing, building, and integrating MCP servers that connect our AI agents to internal tools, financial data systems, and third-party APIs. You'll collaborate closely with product, compliance, and cross-functional engineering teams to build financial technology that's fast, secure, and genuinely intelligent.Responsibilities:Design, build, and continuously improve our LLM-based Agentic platform. Own end-to-end architecture decisions from model orchestration and prompt design to retrieval pipelines, tool-calling patterns, and evaluation frameworks.Architect and build high-performance services in Python and/or Node.js. Design systems for extreme speed, reliability, and real-time data processing under high traffic conditions.Design and maintain MCP servers that give AI agents structured, secure access to internal banking systems, external APIs, databases, and developer tools making Agentic platform composable and extensible by design.Build intuitive React interfaces that expose AI capabilities like chat interfaces, agentic dashboards, real-time streaming UIs, and internal tooling. Own state management patterns and component architecture at scale.Partner with product managers, business stakeholders, compliance, and engineering teams to translate vision into scalable technical requirements and roadmaps.Design and ensure the platform meets enterprise-grade security and financial regulatory standards.Actively upskill fellow engineers on full-stack best practices, LLM integration patterns, and production of AI systems. Help define coding standards and contribute to a culture of engineering excellence.Evaluate emerging models, frameworks, and tooling. Prototype and integrate the most impactful advances into our platform and internal developer productivity tooling.Qualifications:Hands-on production experience with Large Language Models, prompt engineering, RAG workflows, agent frameworks, and LLM evaluation strategies.Experience building and consuming MCP servers.5+ years of professional software development with a proven record on complex full-stack systems.Experience with modern JavaScript (ES6+), React, state management (Redux, Zustand, or similar) at scale.Hands-on experience architecting on AWS (DynamoDB, S3, RDS, Lambda, and API Gateway). Knowledge of Infrastructure as Code (Terraform) is a plus.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.Salary Range: $160,000.00 - $200,000.00Cross River is an Equal Opportunity Employer. Cross River does not discriminate on the basis of race, religion, color, sex, gender identity, sexual orientation, age, non-disqualifying physical or mental disability, national origin, veteran status or any other basis covered by appropriate law. All employment is decided on the basis of qualifications, merit, and business need.By submitting your application, you give Cross River permission to email, call, or text you using the contact details provided. We will only contact you with job related information.