Senior .NET Developer – Legacy Applications

Integrated OS; Muntinlupa; Hybrid; PHP 800,000 - 1,200,000; Full time

Benefits offered by this job

Competitive salary & benefits

Career growth

Work-life balance

Collaborative environment

Job summary

Integrated OS in the Philippines is seeking an experienced .NET Developer – Legacy Applications to join a mature codebase that underpins live operations.

You will maintain, extend and modernize an ASP.NET MVC app and SQL Server data layer, writing clean C# and T-SQL while navigating limited documentation and a long‑running production system. Hybrid work and generous benefits are offered to support you.

Qualifications

• Bachelor's degree in Computer Science, Engineering, or related field.
• 5+ years hands-on .NET development, including ASP.NET MVC on .NET Framework.
• Strong C# and MVC skills with Razor views, routing, and DI.
• Strong SQL Server skills: T-SQL, procedures, indexing, performance tuning.
• Experience with Entity Framework 6, ADO.NET, LINQ to SQL.
• Experience maintaining legacy codebases with limited documentation.
• Proficient in HTML, CSS, JavaScript, jQuery, Bootstrap.
• Experience with IIS and Windows Server hosting.
• Version control experience (Git, TFS/TFVC, SVN) and build/deploy tools (Azure DevOps, TFS).
• Experience developing/consuming APIs (Web API, WCF, REST).

Responsibilities

• Maintain, support and enhance the ASP.NET MVC application for stability and performance.
• Diagnose defects and production incidents; optimize SQL Server queries.
• Develop new features within the existing MVC architecture with clean C# code.
• Write, review and optimize T-SQL and database objects.
• Test and deploy changes carefully in a mature codebase with limited tests.
• Document undocumented areas of the application and database schema.
• Apply framework and security patches; remediate aging dependencies.
• Contribute to modernization toward newer .NET versions.
• Collaborate with stakeholders to translate requests into practical solutions.

Skills

C# & .NET

ASP.NET MVC

SQL Server

Entity Framework

JavaScript

HTML/CSS

Git

Problem solving

Communication

Education

Bachelor's degree in Computer Science or related

Tools

Visual Studio

SQL Server Management Studio

Azure DevOps

Job description

Integrated OS in the Philippines is seeking an experienced .NET Developer – Legacy Applications to join a mature codebase that underpins live operations.

You will maintain, extend and modernize an ASP.NET MVC app and SQL Server data layer, writing clean C# and T-SQL while navigating limited documentation and a long‑running production system. Hybrid work and generous benefits are offered to support you.