Lead System Engineer - Windows ASP.NET Platform

This position requires office presence of a minimum of 5 days per week and is only located in the location(s) posted. No relocation is offered. AT&T will not hire any applicants for this position who require employer sponsorship now or in the future. Join AT&T and help support, strengthen, and modernize the enterprise applications and technologies that keep critical business processes running. The Enterprise Architecture & Service Enablement – Engineering and Operations team (EASE-EO) manages applications, compute infrastructure, and operations. The team designs and implements secure solutions, automation, and operational tooling.  We ensure compliance with vulnerability management requirements, SOX, PCI, and audit controls. When you step into a career with AT&T, you won’t just imagine the future — you’ll help maintain today’s critical systems while modernizing them for tomorrow. What you’ll do: Support, maintain, enhance, and modernize enterprise-grade ASP.NET Web Forms applications hosted on Windows Server and IIS. Provide hands-on application support across C#, JavaScript, CSS, HTML, Visual Studio, Git, SQL Server, Entra ID SSO, OWIN middleware, and related Windows-based application technologies. Drive application reliability, audit readiness, controlled software delivery, and process optimization by learning the existing application architecture, understanding documented SOX control narratives, producing evidence for recurring audit testing, and ensuring code changes are developed, tested, documented, and deployed through established change control processes. Focus on transitioning from legacy, application-specific support practices to more standardized, sustainable operating models by improving documentation, strengthening evidence-generation procedures, reducing manual support effort, enhancing deployment discipline, and preparing the application for future modernization from ASP.NET Web Forms to a newer technology platform. Architecture & Design: Evaluate and support the architecture of a business-critical ASP.NET Web Forms application, including IIS hosting, SQL Server integrations, Entra ID SSO, OWIN middleware, role-based access logic, approval workflows, audit logging, and evidence-producing processes. Identify opportunities to improve reliability, maintainability, documentation, and modernization readiness. Agile & DevOps Enablement: Support Agile and DevOps practices by maintaining disciplined Git-based source control, documenting release procedures, validating application changes, and following established change control processes. Help modernize the deployment model from manual or semi-manual releases toward secure, repeatable CI/CD pipelines using tools such as Jenkins, REVUP, and standardized deployment automation. Data and AI-Enabled Release Management Strategy: Support the evolution from manual or application-specific release practices toward standardized, repeatable, and auditable delivery models. Use application data, SQL Server records, audit logs, change documentation, and operational reporting to improve release readiness, risk assessment, deployment validation, and production reliability. Identify opportunities to introduce automation, analytics, and reporting improvements that reduce manual effort and strengthen change control execution. Requirements & Integration: Translate business, operational, and audit-related needs into technical specifications for application enhancements, defect resolution, reporting, access management, and evidence-generation processes. Support reliable integration across ASP.NET Web Forms, SQL Server, IIS, Windows Server, Entra ID SSO, OWIN middleware, email notifications, and related enterprise infrastructure. Technical Leadership: Guide cross-functional business, application, infrastructure, and support teams through enhancement planning, defect resolution, release readiness, production support, and modernization activities. Align technical solutions with