Senior Specialist, IT Application Solutions - Full Stack Developer

Job Overview 综述

We are seeking a hands-on Full Stack Developer with strong expertise in ASP.NET / .NET (Framework and Core), React, legacy AngularJS, and advanced SQL Server development. This role designs, develops, modernizes, and supports enterprise applications that enable Innovation & Product Management processes and critical T&I initiatives.

You will collaborate closely with application owners, subject matter experts, and IT Business Relationship Managers in a fast-paced environment where iteration speed and execution matter. This role requires a builder mindset—someone who thrives on solving tough problems, shipping quickly, and taking ownership across both front-end and back-end systems.

The ideal candidate is eager to learn and passionate about hands-on building of scalable, efficient applications.

Responsibilities 职责

Full Stack Application Development & Support

• Design, develop, enhance, and maintain full stack applications using C#, ASP.NET, .NET Framework/.NET Core, React, AngularJS, JavaScript, SQL Server, and REST APIs.
• Build responsive UI components and integrate them with backend services and database layers.
• Provide ongoing technical support to internal stakeholders, troubleshooting and resolving application issues with strong ownership and follow-through.
• Identify and reduce technical debt, improve code quality, and recommend platform/architecture uplifts.
  
  

Database Engineering & Performance Optimization

• Design and implement database schemas and data models as needed.
• Write and tune complex SQL Server queries, stored procedures, and performance-critical data access patterns.
• Diagnose and resolve performance bottlenecks across application and database tiers.
• Build data-intensive solutions that interact with Snowflake and SQL Server as data sources
  
  

Application Migration & Modernization

Support the migration and modernization of one or more existing Python/Django applications hosted on Linux in Azure to a .NET Core target-state hosted on Azure App Services and Azure Web/API services.

• Analyze existing Python/Django application architectures, including routing, controllers, business logic, and data access patterns.
• Design and implement a target-state ASP.NET Core architecture in collaboration with Celanese IT resources.
• Rewrite and refactor Python-based logic into native C# services, ensuring functional parity, performance, and long-term maintainability.
  
  

Support the migration and refactoring of existing DevExpress-based ASP.NET applications to modern UI architectures (React or native ASP.NET Core patterns).

• Reduce reliance on proprietary UI components while preserving required functionality.
• Improve application performance, usability, and extensibility.
• Align legacy applications with modern development standards to ensure long-term supportability and scalability.
  
  

DevOps, CI/CD, and Azure Cloud Delivery

• Contribute to CI/CD pipelines, DevOps practices, and Azure cloud deployments.
• Support Azure best practices for configuration management, logging, monitoring, environment separation
• Work within Azure DevOps tooling and support transition to GitHub workflows
  
  

Quality, Validation & Documentation

• Maintain functional parity during migrations with automated testing and side by-side validation where appropriate
• Support phased or incremental cutover strategies to reduce risk and downtime.
• Produce technical documentation, including architecture decisions, migration approproaches/mappings, operational runbooks / support guides
  
  

Qualifications 要求

Must Have Technical Skills:

• .NET / C#: 5+ years hands-on development with C# and ASP.NET (either .NET Framework and/or .NET Core).
• Front-End: Strong experience building web UIs with React and JavaScript (HTML/CSS included). Ability to work in/around legacy AngularJS codebases (support/maintenance and basic modernization).
• Ability to work in/around legacy AngularJS codebases (support/maintenance and basic modernization).
• Strong understanding of .NET Framework and libraries for backend logic.
• SQL Server: expertise in SQL Server development including complex queries / joins, stored procedures, performance tuning, reporting services (SSRS)
• APIs: Proven experience building and integrating RESTful APIs (design, implementation, consumption).
• Azure: Working experience deploying/supporting applications in Microsoft Azure, specifically, Azure App Services and/or Web/API hosting patterns
• Azure DevOps, Git, and CI/CD pipelines.
• Production Support: Experience supporting enterprise applications in production (troubleshooting, root cause analysis, fixes).
• Documentation & Communication: Ability to document solutions clearly and communicate with both technical and non-technical stakeholders.
• Experience with Agile/Scrum methodologies.
  
  

Qualifications

• Bachelor’s degree in Computer Science, Information Systems, Engineering, or related field.
• 5–7 years professional full stack development experience (front-end + back-end + database).
• Microsoft certifications are a plus.
  
  

Nice To Have Previous Experience In

• Python/Django → .NET Core migrations (or comparable cross-stack migrations) refactoring monolithic apps into service layers / clean architectures
• DevExpress modernization : Refactoring DevExpress-based ASP.NET apps to modern UI stacks (React or ASP.NET Core patterns).
• Snowflake integration : Data-intensive application experience using Snowflake as a source (in addition to SQL Server).
• Previous collaboration with data scientists and integration with Python-based tools.