Senior Full Stack Software Engineer

ABOUT DEFCON AI RESILIENCE IN THE FACE OF DISRUPTION. DEFCON AI is an insights company that leverages artificial intelligence, mathematical optimization, data analytics, and software engineering for resilient optimization of complex systems. In today’s dynamically changing world, DEFCON AI’s technology aligns outcomes with operational goals, better decision making, and empowers customers to anticipate assess, and mitigate the impacts of disruptions. About the Role We’re hiring a Senior Full Stack Software Engineer to design, build, and scale modern web applications end-to-end. You’ll work across frontend UI, backend services, APIs, asynchronous processing, and data layers—shipping features that are reliable, secure, and built to last. This is a senior individual contributor role with real autonomy and real impact. You’ll have end-to-end ownership of features and meaningful input into technical decisions, quality standards, and delivery practices working in a remote-first environment. Core Tech Stack: Frontend : React 19, TypeScript, Vite-based React apps, Tailwind CSS, SignalR Backend: .NET 9 (C#), Minimal APIs, Entity Framework Core Async Processing: RabbitMQ, Redis (for scale-out and caching) Data and Storage: PostgreSQL, Amazon S3 What You’ll Do Shape the product architecture end-to-end. You’ll design and ship modular .NET services and modern React frontends that stay fast, reliable, and elegant across a wide range of real-world customer environments. Own the data foundation. You’ll design high-performance PostgreSQL schemas and craft EF Core queries that serve as the source of truth for business logic, permissions, and RBAC—balancing correctness, clarity, and scale. Engineer for performance at scale. You’ll build smart caching layers with Redis and leverage S3 for large artifacts, keeping our Web Gateway lean, responsive, and built to grow. Drive technical direction through RFCs. You’ll author and collaborate on design proposals that define data contracts and API boundaries, making our .NET platform and Python-based solver runners work together seamlessly. Ship with product and design, not in a silo. You’ll partner closely with product and design to turn real customer problems into thoughtful technical solutions—and deliver them in tight, iterative releases. Use AI as a force multiplier (responsibly). You’ll leverage tools like Claude Code and GitHub Copilot/Cursor to move faster and refactor with confidence, while keeping security, quality, and maintainability non-negotiable. Hold the quality bar high. You’ll help set the standard through great code reviews, automated testing, and pragmatic engineering practices that keep the codebase a joy to work in. What We’re Looking For (Required) 8+ years of professional software engineering experience delivering production web applications. Strong full stack experience shipping user-facing features end-to-end across frontend, backend, and data layers. Deep expertise in React and TypeScript , including component architecture, hooks, and performance optimization. Experience building and maintaining modern React applications (Vite, Tailwind CSS and client-side data fetching patterns). Strong backend experience with C# and modern .NET (.NET 9 or similar), including API design with Minimal APIs and secure development practices. Strong experience with PostgreSQL , including schema design, indexing strategies, and query optimization. Hands-on experience with Entity Framework Core , including writing efficient queries and managing migrations. Experience designing and operating asynchronous workflows (RabbitMQ) and implementing caching strategies (Redis). Experience building real-time UI updates using SignalR. Experience working with AWS , especially object storage in Amazon S3. Solid understanding of authentication or authorization patterns including application-level RBAC (e.g., JWT, OAuth/OIDC concepts). Strong written and verbal commun ... (truncated, view full listing at source)