About DragonPay DragonPay is a fintech startup building modern payment solutions for U.S. credit unions. Our platform enables financial institutions to offer innovative payment experiences through their existing digital banking applications. We're building a small, experienced engineering team where each developer has meaningful ownership and contributes directly to the design, development, and delivery of our products. AI\-assisted development is fundamental to how we work. We use AI coding tools extensively throughout the software development lifecycle, allowing engineers to focus more on architecture, problem\-solving, code review, testing, and product quality rather than writing every line of code. About the Role We're looking for a Senior Full Stack Engineer with strong front\-end expertise and experience integrating software into third\-party applications. A central responsibility of this position is designing and building flexible application integration capabilities. Our products must integrate seamlessly with existing digital banking platforms through multiple approaches, including hosted applications, embedded experiences, reusable SDK components, and headless API integrations. You'll own front\-end architecture and development, ensuring our applications can be securely and efficiently integrated into different third\-party environments without requiring separate implementations for every customer. You'll collaborate closely with our technical lead and other engineers on APIs, integrations, and shared platform capabilities. Responsibilities * Design, develop, and maintain modern web applications using React, Next.js, and TypeScript. * Architect reusable front\-end solutions supporting hosted, embedded, SDK\-based, and headless integration models. * Build reusable JavaScript/TypeScript SDKs and UI components that third\-party developers can easily integrate into their applications. * Develop secure application launch, authentication, session management, and cross\-application communication capabilities. * Design flexible, white\-label user interfaces that adapt to different customer brands and host environments. * Build and maintain developer\-friendly integration interfaces, packages, and documentation. * Develop internal administrative and operational applications. * Collaborate on API design and implement supporting back\-end functionality when needed. * Ensure applications meet high standards for security, performance, accessibility, and usability. * Develop and maintain automated tests across supported integration environments. * Participate in architecture discussions, technical planning, and peer code reviews. * Use AI\-assisted development tools extensively for planning, implementation, testing, debugging, and refactoring. * Review and validate AI\-generated code for correctness, security, and maintainability. * Take ownership of features from initial requirements through production delivery. Required Qualifications * Strong professional experience developing production web applications with React, Next.js, and TypeScript. * Experience designing or implementing software that integrates into third\-party web applications, including embedded experiences, JavaScript SDKs, or reusable component libraries. * Strong understanding of application integration patterns, browser security boundaries, cross\-origin communication, and host\-application interaction. * Experience with authentication and authorization, including OAuth 2\.0, OpenID Connect, or similar technologies. * Experience with Node.js and NestJS or similar back\-end frameworks. * Strong understanding of modern front\-end architecture, component design, and state management. * Experience designing and consuming REST APIs. * Understanding of application security, performance optimization, responsive design, and accessibility. * Experience with automated testing, including component and end\-to\-end testing. * Working knowledge of Git, CI/CD pipelines, and cloud\-hosted applications. * Practical experience using AI coding assistants, with the ability to critically evaluate their output. * Strong problem\-solving skills and the ability to work independently in a small engineering team. Preferred Qualifications * Experience in fintech, banking, payments, or other regulated industries. * Experience designing, packaging, versioning, and distributing JavaScript/TypeScript SDKs for external developers. * Experience integrating software into established enterprise platforms or digital banking applications. * Familiarity with digital banking platforms such as Q2, Alkami, or Lumin. * Experience supporting multiple integration models for the same underlying application. * Experience building developer\-facing integration documentation and reference implementations. * Familiarity with AWS and containerized environments. * Experience with Playwright or comparable end\-to\-end testing frameworks. * Experience building administrative dashboards or oper