Senior Back-End Engineer Node.js

Description We are At Cross River, we're building the financial infrastructure that powers global innovation. With our cutting-edge suite of embedded payments, cards, and lending solutions, we enable millions of businesses and consumers to transact seamlessly and securely. With 900+ employees worldwide and an R&D center of over 160 employees in Jerusalem - we’re reshaping how financial technology is developed and delivered. . The Role We are looking for 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. Who You Are You have experience building Retrieval‑Augmented Generation (RAG) systems or knowledge‑base chatbots. You're Hands‑on with vector databases such as Pinecone, Chroma, or pgvector on Postgres/Aurora. Have AWS certification (Developer, Solutions Architect, or Machine Learning Specialty). Experience with observability tooling (Datadog, New Relic) and cost‑optimization strategies for AI workloads. Background in microservices, domain‑driven design, or event‑sourcing patterns. What You’ll Actually Be Doing 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. Requirements What You Bring to the Table Available working some US hours Proficient in Hebrew and English both written and verbal, sufficient for achieving consensus and success in a remote and largely asynchronous work environment - Must 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. Why You’ll Love Working Here Flexible hybrid model: 3 days a week in the office – A must ₪1,000 net monthly wellness benefit – from therapy to Pilates to your kid’s art class Full Keren Hishtalmut, private health & dental insurance Donation matching, volunteering days, team outings, and mentorship programs A mission-driven culture that values ownership, trust, and meaningful impact Next Step Hit Apply! Privacy Notice: Cross River https://www.crossriver.com/legal/privacy-policy-crt