Fullstack Software Dev Engineer II

Yahoo is a leading technology company that connects brands and partners with a vast audience. They are seeking a Fullstack Software Dev Engineer II to join their Identity organization, where the role involves building secure, scalable authentication and account management systems for millions of users globally.

Responsibilities:

• Design, build, and operate secure, scalable full-stack identity systems using ReactJS, TypeScript, Java, and Node.js
• Own complex features and standalone project phases end-to-end, from gathering requirements and systems design to implementation, testing, and production
• Lead an AI-first development workflow within the squad, writing precise markdown specifications to drive AI-assisted code generation (Cursor, Claude Code), and taking responsibility for the rigorous validation, testing, and safety of all generated assets
• Identify system bottlenecks, enhance platform reliability, and debug complex production issues in our high-traffic distributed identity systems
• Proactively research and implement AI-driven efficiencies in your daily coding workflows, replacing repetitive manual tasks with structured automation, custom templates, and AI-assisted testing
• Act as a technical resource for the team by sharing successful prompt engineering patterns, context modeling strategies, and workflow optimizations that level up the overall engineering velocity of the squad
• Collaborate cross-functionally with Product Managers, UX Designers, Security Engineers, and other Yahoo product squads to coordinate technical integrations

Requirements:

• Bachelor's degree in Computer Science, a related technical field, or equivalent practical experience
• 4–6 years of professional full-stack software engineering experience
• Strong hands-on engineering experience using Java for robust backend services
• Experience building responsive, high-performance web applications using React.js, Node.js, JavaScript/TypeScript, and modern frameworks such as Next.js
• Strong core engineering fundamentals in distributed system design, API development, databases, and web security
• Demonstrated experience integrating AI-assisted developer tools (e.g., Cursor, Claude Code, GitHub Copilot) into day-to-day software development workflows to build and refactor production-grade systems
• Practical understanding of prompt engineering, model limitations, and structured context assembly to generate robust code outputs
• Proven capability to evaluate, audit, and debug AI-generated outputs, ensuring alignment with Yahoo's high standards for code quality, security protocols, and performance
• Experience with testing frameworks, CI/CD pipelines, and writing production-ready, highly maintainable tests
• Experience building or maintaining high-scale Identity and Access Management (IAM) systems, auth protocols (OAuth, OIDC, SAML), or web security standards
• Cloud platform experience (GCP, AWS, or Azure) and infrastructure-as-code
• Familiarity with observability tools (Splunk, Grafana) and client/server performance profiling
• Experience with structured development methodologies, such as Spec-Driven Development (SDD), API-first design, or AI-assisted diagnostic tools
• Exposure to web accessibility (WCAG), internationalization, or large-scale consumer product delivery