Senior Fullstack Engineer

Senior Full Stack Engineer to design, build, and operate secure, scalable products and integrations across our global mobility platform. You will deliver hands-on engineering across Next.js and React front ends and C# and .NET services running on Microsoft Azure, operating in a regulated, global environment. This role is for an experienced engineer who can own end-to-end features, contribute to architectural decisions, and consistently deliver production-ready solutions using agentic development practices including spec-driven development and agent-driven development with tools such as Claude Code and Codex. You will build AI-native products and workflows, integrating AI capabilities directly into the applications and services you deliver. What You'll Do · Build and evolve modern web experiences using Next.js, React, and TypeScript with a focus on performance, reliability, and usability. · Design and implement backend services and APIs using C#, .NET, and WebAPI, including integrations that support payroll, tax, and immigration workflows. · Deliver Azure-native implementations using Microsoft PaaS services, secure patterns, and operational best practices. · Contribute to system architecture and technical design, including integration patterns using REST and event-driven approaches. · Own production readiness for your work including logging, monitoring and alerting, incident response support, and operational documentation. · Apply secure development practices appropriate for regulated environments including privacy, auditability, and data protection. · Partner with product, implementation, and client-facing teams to translate requirements into technical plans and deliverables. · Use agentic development practices including agent-driven development with Claude Code, Codex, or similar AI coding agents to accelerate design, implementation, testing, and operations across the SDLC. · Work in a spec-driven development workflow, authoring detailed specifications that guide both human and AI agent implementation, translating clear requirements into predictable delivery and maintainable code. · Design and implement AI-powered features within products including prompt engineering, LLM integration, retrieval-augmented generation (RAG) patterns, and AI-assisted user workflows. · Evaluate, integrate, and operationalize AI APIs, models, and toolchains within application architectures, ensuring responsible AI usage, cost management, and observability. · Mentor and support other engineers through code reviews, pairing, and technical guidance. Required Qualifications · 5+ years professional software development experience building enterprise web applications and services. · Strong experience designing and building large JavaScript applications with Next.js and or React (TypeScript, state management, performance optimization). · Strong backend development experience in C# and .NET (ASP.NET, WebAPI, MVC) including API design and service patterns. · Proven experience with Microsoft Azure designing and building cloud solutions using PaaS services, frameworks, and operational tooling. · Experience delivering systems in regulated or compliance-oriented environments (security controls, auditability, privacy, data handling). · Strong engineering fundamentals including design patterns, separation of concerns, scalable architecture, and pragmatic trade-offs. · Experience with agentic or AI-assisted development workflows such as spec-driven development, agent-driven development using tools like Claude Code or Codex, or similar AI coding agent practices. · Demonstrated ability to build products that incorporate AI capabilities including prompt design, LLM API integration, or AI-augmented user experiences. Preferred Qualifications · Azure certifications and/or Microsoft certifications. · Experience with event-based and distributed systems including messaging and asynchronous workflows. · Data and persistence experience with SQL Server and ORMs (Entity Framework, nHibernate) plus caching strategies. · Strong testing discipline including TDD and BDD, xUnit, Jest or Mocha, CI/CD automation, and quality gates. · Experience building analytics and reporting with BI and data visualization tools and domain-specific reporting. · Exposure to mobile ecosystems (iOS and Android) and API design supporting mobile clients. · Experience with prompt engineering patterns, RAG architectures, vector databases, or AI orchestration frameworks (e.g., LangChain, Semantic Kernel, Azure AI Services). · Familiarity with AI code generation and review workflows, including evaluating and curating AI-generated code for production readiness. · Experience contributing to or building AI-augmented internal tools, developer experience tooling, or intelligent automation within engineering workflows. Technical Skills We Value · Frontend: Next.js, React, TypeScript, HTML, CSS, SPA architecture, performance and accessibility · Backend: C#, ASP.NET, WebAPI, RESTful design, authentication and authorization patterns · Cloud: Azure PaaS services, observability, secure networking, identity, deployment automation · Engineering practices: Git-based workflows, secure SDLC, spec-driven development, AI-assisted code reviews, automated testing, documentation · AI-enabled delivery: agentic development using Claude Code, Codex, or similar AI coding agents; spec-driven development workflows; prompt engineering; LLM API integration; RAG patterns; AI orchestration frameworks; responsible AI practices and observability What Success Looks Like · Delivers complex features end-to-end with high quality, predictable timelines, and production readiness. · Produces clean, maintainable code—whether hand-written or AI-generated—with strong test coverage and clear documentation. · Identifies and resolves performance, reliability, and security issues before they reach production. · Contributes meaningfully to architecture and raises standards through code reviews and technical leadership. · Communicates clearly, flags risks early, and collaborates effectively across teams. · Effectively leverages agentic development tools and AI-augmented workflows to increase velocity while maintaining quality and security standards. Education · Bachelor's degree in Computer Science, Engineering, or related field required. · Master's degree preferred.