Full Stack .NET Developer

Simon & Schuster, one of the world's leading publishers, is investing in a multi-year modernization of the core systems that power order management, fulfillment, partner integration, and financial transactions. We are replacing long-established technology with modern .NET and SQL solutions using an AI-assisted approach. The program is already delivering measurable performance improvements in production.

The Full-Stack .NET Developer is the hands-on builder on the modernization team. You will take legacy batch programs and, working from documented business requirements, replace them with modern, production-grade .NET services and SQL solutions that are validated in parallel against the existing system before every cutover. As the program advances, the role extends to modern web front ends that replace legacy green-screen workflows, which is why full-stack capability matters.

AI tooling is central to how this team works: AI assists with legacy analysis, code generation, test generation, and documentation. You will use these tools daily — and you will be expected to review, refine, and validate AI-generated code critically rather than accept it blindly.

• Build modern replacements — Implement .NET worker services, APIs, and T-SQL stored procedures that replace legacy COBOL batch programs while preserving required business behavior.
• Review and refine AI-generated code — Use AI-assisted development for speed, then apply engineering judgment: correctness, edge cases, error handling, performance, and maintainability are yours to guarantee.
• Implement target architecture patterns — Apply the program's established patterns: structured logging and run telemetry, configuration-driven behavior, parallel-run ("shadow") support, restartability, and clean integration contracts.
• Support validation and cutover — Instrument every replacement for reconciliation against legacy output; work with the QA / Test Automation Engineer to drive each package to a clean validation gate before production cutover.
• Resolve complex conversion issues — Debug behavioral differences between legacy and modern implementations, working with legacy specialists to understand what the original code actually does.
• Front-end development — Build and maintain modern web UI components as the program modernizes user-facing workflows (browser-based replacements for legacy green-screen transactions).
• Contribute to engineering standards — Capture lessons learned, improve shared frameworks and templates, and help raise the quality bar as the team scales.

• 5+ years of professional full-stack .NET development — C#, .NET (modern .NET 6+ preferred), building and operating production services.
• Experience using AI tools to assist development — e.g., AI-assisted code generation, code review, test generation, or documentation — with the judgment to critically validate generated output before it ships.
• Strong SQL Server / T-SQL skills — stored procedures, set-based logic, transactions, and query-performance fundamentals.
• Back-end service experience — background/worker services, scheduled or batch processing, structured logging, and configuration management.
• Front-end web development experience — modern web UI with ASP.NET Core (Razor/Blazor) or a JavaScript/Type Script framework (React, Angular, or similar).
• Production mindset — experience owning code that runs unattended in production: error handling, restartability, observability, and safe deployment practices.
• Strong debugging and problem-solving skills, including reasoning about data-level differences between two systems.
• Clear written communication — design notes, code review feedback, and operational documentation.

• Experience…