Senior Fullstack Developer (NodeJS/ ReactJS

10+ years designing, building, and maintaining applications front-end to back-end.5+ years as the senior or lead engineer owning a production system end-to-end (design, build, release, and support).A proven record of taking over an unfamiliar, business-critical codebase and changing it safely.5+ years with Microsoft SQL Server as the primary database, including schema design and safe evolution of a substantial relational model (100+ tables) using hand-written sequential migration scripts.Production RESTful APIs in Node.js/Express using the mssql driver, with connection-pool resilience, timeouts, request validation, server-side error handling, and crash-resilient behavior.React + TypeScript features built from UI through hooks to a typed API client.Integration with enterprise systems of record (ERP, document/content management) including idempotent sync, retries, paging, delta checkpoints, and reconciliation.Maintaining a React Native mobile app inside a restricted network.Security in regulated environments (authentication, session handling, server-side RBAC, secure coding to OWASP ASVS, NIA, ISO 27001 standards).Manual, script-based deployment and operations on Windows Server without cloud CI/CD, and working productively offline without internet access. 10+ years designing, building, and maintaining applications front-end to back-end.5+ years as the senior or lead engineer owning a production system end-to-end (design, build, release, and support).A proven record of taking over an unfamiliar, business-critical codebase and changing it safely.5+ years with Microsoft SQL Server as the primary database, including schema design and safe evolution of a substantial relational model (100+ tables) using hand-written sequential migration scripts.Production RESTful APIs in Node.js/Express using the mssql driver, with connection-pool resilience, timeouts, request validation, server-side error handling, and crash-resilient behavior.React + TypeScript features built from UI through hooks to a typed API client.Integration with enterprise systems of record (ERP, document/content management) including idempotent sync, retries, paging, delta checkpoints, and reconciliation.Maintaining a React Native mobile app inside a restricted network.Security in regulated environments (authentication, session handling, server-side RBAC, secure coding to OWASP ASVS, NIA, ISO 27001 standards).Manual, script-based deployment and operations on Windows Server without cloud CI/CD, and working productively offline without internet access.