Senior Full Stack Developer (Node.js/React)

Full Stack Developer BillingPlatform is an industry-leading, fast-growing SaaS company. Our award-winning, cloud-based revenue lifecycle management platform is leveraged by leading global enterprises to automate and streamline the entire quote-to-cash process. At BillingPlatform, our employees are our most valuable asset, and we believe deeply in a culture of collaboration, accountability, innovation, and transparency. We seek bright, enthusiastic, and creative professionals looking to be part of our incredible team focused on challenging the status quo and driving transformational value to customers. Backed by leading private equity firms FTV Capital and Columbia Capital, we have achieved remarkable industry recognition for growth, including being listed for the fifth consecutive year on Deloitte’s Technology Fast 500™ list of fastest-growing technology companies and ranked on the Inc. 5000 list for six years running. Our ability to innovate market-leading solutions has been validated by all major industry analyst firms, including being named a Leader in the first-ever Gartner® Magic Quadrant™ for Recurring Billing Applications and being recognized as the Leader in Forrester Research’s “The Forrester Wave™: SaaS Recurring Billing Solutions.” Role Description: We are seeking a Senior Full Stack Developer to join our AI team and contribute to the development and improvement of AI Copilot and AI Agents for the BillingPlatform platform. This is a hands-on full-stack engineering role working across React/TypeScript frontend development and Node.js/TypeScript backend services, APIs, integrations, and AI-agent tooling. Responsibilities: Develop and maintain React/TypeScript components. Build and maintain backend services using Node.js, TypeScript, and Express. Design clear, typed contracts for APIs and MCP tools using TypeScript and schema validation. Develop and integrate REST APIs and internal and third-party services. Write and maintain unit and integration tests. Troubleshoot and resolve issues across the application stack. Participate in code reviews and follow internal reuse, security, and testing conventions. Collaborate with backend teams on API contracts, data models, and integration architecture. Use AI coding agents as part of the development workflow. Contribute to the development of AI Copilot and AI Agent capabilities. Qualifications: 4+ years of experience with Node.js and Express 2+ years of professional experience with React and TypeScript. Strong TypeScript fundamentals, including generics, utility types, type narrowing, and typed API contracts. Strong understanding of MCP principles. Experience building AI agents. Experience designing and consuming REST APIs. Good understanding of asynchronous JavaScript, Promises, async/await, and error handling. Experience with schema validation libraries such as Zod or similar. Familiarity with Jest, component testing, mocking, and integration testing practices. Understanding of common web security concepts, including CORS, CSRF, input validation, secrets handling, and OWASP fundamentals. Exposure to Model Context Protocol (MCP), AI agent tooling, LLM tool/function calling, or building LLM-facing APIs. Practical experience using AI coding agents such as Codex or Claude Code for code generation, refactoring, testing, and debugging. Preferred skills: Experience with AWS Bedrock. Prior experience with fintech or financial systems. Experience working with sensitive customer or financial data. Experience with AWS services and production cloud environments. Docker experience. Experience with OpenAPI/Swagger and API contract documentation. Familiarity with observability tooling, structured logging, metrics, and production debugging. Understanding of API reliability patterns such as retries, timeouts, rate limiting, and idempotency. Experience designing tools or APIs specifically for LLM agents. Experience evaluating or debugging AI-agent workflows and tool calls. Benefits: Opportunity to contribute to global initiatives and work with an international team. A high-impact role at a growing SaaS company that values personal growth, accountability, and teamwork. Supportive, transparent culture focused on open communication and problem-solving. Company-sponsored English lessons for non-native speakers to support ongoing language development. Fully remote work environment. Competitive pay. BillingPlatform provides equal employment opportunity (EEO) to all persons regardless of age, color, national origin, citizenship status, physical or mental disability, race, religion, creed, gender, sex, pregnancy, sexual orientation, gender identity and/or expression, genetic information, marital status, status with regard to public assistance, veteran status, or any other characteristic protected by federal, state or local law.