Full Stack .NET Developer

Simon & Schuster•New York, NY

2d•$120,000 - $150,000•Onsite

About The Position

Simon & Schuster, a global leader in publishing, is undergoing a multi-year modernization of its core systems, including order management, fulfillment, partner integration, and financial transactions. This initiative involves replacing legacy technology with modern .NET and SQL solutions, utilizing an AI-assisted approach to achieve measurable performance improvements. The Full-Stack .NET Developer will be a key hands-on contributor to this modernization program. The role involves transforming legacy batch programs into modern .NET services and SQL solutions, ensuring they are validated against existing systems before deployment. As the program progresses, the role will expand to include the development of modern web front ends to replace legacy green-screen workflows, necessitating full-stack capabilities. AI tooling is integral to the team's workflow, assisting in legacy analysis, code generation, test generation, and documentation. Developers are expected to critically review, refine, and validate AI-generated code.

Requirements

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/TypeScript 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.

Nice To Haves

Experience on a legacy-modernization, system-replacement, or platform-migration program.
Exposure to legacy or mainframe-style environments (e.g., COBOL-era batch systems) — enough familiarity to work effectively with legacy specialists when analyzing existing behavior. No COBOL programming required.
Order processing, fulfillment, supply-chain, or EDI domain experience.
Data-access frameworks such as Dapper or Entity Framework Core.
Batch scheduling environments (AutoSys or similar) and overnight batch operations.
Azure experience — SQL Server on Azure VMs, Azure SQL Managed Instance, or Azure-hosted services.
Automated testing practices — unit testing, integration testing, or test-driven development.

Responsibilities

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.