Justin Mangum

Plano, TX 75023 | 682-582-4787 | [email protected] | LinkedIn

.NET Technical Lead

Seasoned technology professional with extensive software development experience leading the design, development, and implementation of enterprise applications and cloud-native solutions.

Proven success modernizing legacy platforms into scalable microservices architectures, improving system availability to 99.9%, and driving engineering best practices across cross-functional teams. Deep expertise in C#, ASP.NET MVC, .NET, Azure, SQL Server, REST APIs, and distributed systems, with a strong background in backend services, automation, DevOps, and reusable framework development. Stellar record of translating complex business requirements into scalable technical solutions while mentoring development teams and establishing engineering standards that improve long-term maintainability. Recognized for combining technical leadership with hands-on engineering to deliver secure, high-performance solutions that improve reliability, accelerate delivery, and solve complex business challenges.

CORE COMPETENCIES

.NET Application Development | Technical Leadership | Software Architecture | Microservices Architecture | Cloud Solutions

Software Development Life Cycle (SDLC) | Full Stack Development | Enterprise Application Development | REST API Development

Distributed Systems | Full Stack Development | Enterprise Application Development | System Modernization | Performance & Scalability

Database Design & Optimization | DevOps & Build Automation | Cross-Functional Collaboration | Team Leadership

TECHNICAL SKILLS

•         Programming Languages & Web Technologies: C#, Java, JavaScript, Python, PHP, SQL, PowerShell, HTML5, CSS3, jQuery
•         Frameworks & Libraries: .NET, ASP.NET MVC, Entity Framework, Xamarin.Forms, WPF, Caliburn.Micro, Caliburn.Metro
•         Architecture & Design Patterns: MVC, MVVM, Object-Oriented Programming (OOP)
•         Cloud & Platforms: Microsoft Azure, Azure Notification Hubs, Azure DocumentDB (Cosmos DB)
•         Development Tools & Databases: Visual Studio, SQL Server, MySQL
•         Microsoft Technologies: Active Directory, Group Policy (GPO), Windows Management Instrumentation (WMI), System Center Configuration Manager (SCCM 2007/2012), Microsoft Application Virtualization (App-V 4.x/5.x)
•         Networking & Integration: REST APIs, API Integration, TCP

PROFESSIONAL EXPERIENCE

Altice USA – Plano, TX

Senior Software Developer |November 2019 to April 2026

Architected and developed a multi-tenant PBX platform supporting multiple business units, delivering scalable voice communication services through modern backend design and automation. Established a centralized on-premises NuGet package repository and reusable shared libraries (database access, SSH/SCP, common models, and utilities), standardized development practices, accelerated delivery, and improved code maintainability across the engineering team.

•         Spearheaded the transformation of a legacy monolithic Windows application into a distributed microservices architecture across CentOS and Ubuntu servers, resulting in increasing platform availability to 99.9% and eliminating recurring nightly outages.
•         Provided technical leadership to an 8-developer software engineering team and drove architectural decisions, code quality, and successful project delivery.
•         Developed and supported enterprise systems serving 10,000+ employees, delivering scalable, high-performing, and reliable business-critical solutions.
•         Engineered high-performance C# Web APIs and backend automation services that streamlined business processes, improved system reliability, and enabled seamless integration between enterprise applications.

Christus Health – Irving, TX

Web Application Developer II | March 2015 to November 2019

Modernized legacy business applications by designing and developing custom, database-driven web solutions using ASP.NET MVC and Entity Framework, improving maintainability, scalability, and user experience. Collaborated across cross-functional development teams to deliver full-stack web applications using C#, ASP.NET MVC, Entity Framework, JavaScript, jQuery, Bootstrap, HTML5, and CSS3 while consistently providing high-quality software solutions.

•         Developed secure, high-performance RESTful APIs that enabled seamless integration between frontend and backend systems, accelerating development and supporting scalable enterprise applications.
•         Formulated enterprise-wide solutions, including a hospital downtime notification platform and a Vendor Finance system processing thousands of payments and millions of dollars daily, which enhanced operational efficiency, communication, and financial accuracy.
•         Designed and implemented an automated financial validation system for the Vendor Finance team and proactively identified payment discrepancies and balance issues before check processing, which improved accuracy and reduced manual review.

Client Device Engineer | March 2013 to March 2015

Administered and optimized Microsoft System Center Configuration Manager (SCCM 2012) and managed enterprise application deployments, software distribution, asset intelligence, server maintenance, and platform troubleshooting across a large healthcare environment. Created technical documentation, standard operating procedures (SOPs), and training materials while mentoring IT staff on application packaging and enterprise deployment best practices.

•         Automated administrative and deployment processes through PowerShell scripting, which resulted in improving operational efficiency and minimizing manual effort for endpoint management tasks.
•         Engineered and maintained Microsoft Application Virtualization (App-V 5.0) solutions integrated with SCCM, packaging enterprise applications and establishing deployment standards adopted across the organization.
•         Designed and developed an enterprise-wide downtime notification platform that delivered real-time push notifications for outages, maintenance windows, and system availability to targeted users and devices.
•         Architected a scalable notification infrastructure leveraging TCP communications, Active Directory–based user, group, and device targeting, and load-balanced notification servers to provide reliable enterprise messaging.
•         Extended the notification platform across desktop and mobile environments by developing companion applications for Android, Windows Phone 8, and Windows 8.1, enabling consistent cross-platform communication for critical operational events.

Texas Health Resources – Arlington, TX

Desktop Engineer |March 2011 to March 2013

Administered and optimized enterprise endpoint management infrastructure using Microsoft SCCM 2007 and App-V 4.5/5.0 and oversaw application packaging, software deployment, operating system imaging, asset intelligence, and platform health across a large healthcare environment. Served as the sole administrator of the Microsoft App-V environment, focused on managing virtualization infrastructure, packaging enterprise applications, and ensuring reliable software delivery to end users. Maintained the health and availability of critical SCCM infrastructure by troubleshooting distribution points, management points, PXE services, certificates, SQL integrations, and client health issues.

•         Engineered SQL and WQL reporting solutions, implemented SQL Server Reporting Services (SSRS), provided actionable operational insights, and improved visibility into enterprise assets and deployments.
•         Enhanced enterprise imaging and deployment processes by developing and maintaining SCCM task sequences, which reduced workstation provisioning time and streamlined device readiness.
•         Designed and developed enterprise support utility that enabled end users to submit service requests, initiate live support sessions, perform automated workstation diagnostics, and self-remediate common configuration issues without IT intervention.
•         Built an advanced toolkit for IT administrators featuring remote diagnostics and repair, Active Directory management, SCCM administration, process management, workstation provisioning, and device location capabilities, which significantly improved technician productivity and response times.
•         Recognized with two organizational awards for developing innovative internal software solutions that automated IT workflows, accelerated service delivery, and improved operational efficiency across the department.

PERSONAL SOFTWARE DEVELOPMENT PROJECTS

•         Developed several IRC and Telegram chatbots, integrating SQL-backed data storage, TCP communications, and REST APIs to deliver scalable, automated messaging solutions.
•         Built an award-winning, open-source Telegram platform serving 7.6M+ players across 1.3M+ groups, earning a $50,000 Telegram developer grant while implementing automated deployment pipelines, SQL-backed infrastructure, and high-availability architecture.
•         Designed and developed multiple personal applications to expand expertise in modern software development, utilizing Xamarin.Forms, Microsoft Azure, Notification Hubs, DocumentDB (Cosmos DB), Project Oxford, LUIS, and Cognitive Services APIs.
•         Applied best practices in cloud-native development, automation, API integration, and scalable application design through continuous development of open-source and personal software projects.