Senior Principal C#/.NET Engineer - Mission-Critical

AllSTEM Connections; Westford (MA); On-site; USD 120,000 - 160,000; Full time

Job summary

AllSTEM Connections is seeking a seasoned Sr. Principal C#/.NET Engineer to lead the enhancement of a mission-critical security integration platform. In this role, you will tackle architectural challenges and ensure high reliability of the system. The ideal candidate will possess expert-level C# capabilities and 7–10 years of backend software engineering experience.

This position offers a chance to work with advanced technologies and to mentor junior engineers as part of a dynamic team. Apply today to make an impact in security integration!

Qualifications

• 7-10 years of professional software engineering experience focused on backend systems.
• Proven ability to work independently in a contract environment.
• Strong experience leveraging AI for development acceleration.

Responsibilities

• Design, implement, and optimize high-performance C# services.
• Lead architectural improvements for legacy components.
• Troubleshoot and resolve deep-level bugs across the system.
• Author technical documentation for complex APIs.
• Provide mentorship to mid-level engineers.

Skills

Expert-level C#

Multi-threaded programming

Networking protocols

AI Integration

Education

Bachelor's or Master's in Computer Science or related

Tools

SQL Server

Azure DevOps

GitHub Actions

ADO.NET

Entity Framework

Job description

AllSTEM Connections is seeking a seasoned Sr. Principal C#/.NET Engineer to lead the enhancement of a mission-critical security integration platform. In this role, you will tackle architectural challenges and ensure high reliability of the system. The ideal candidate will possess expert-level C# capabilities and 7–10 years of backend software engineering experience.

This position offers a chance to work with advanced technologies and to mentor junior engineers as part of a dynamic team. Apply today to make an impact in security integration!