Sr. Principal C#/.NET Engineer

Job Description

Job Description

Key Responsibilities:
Serve as a principal-level contributor on the Crossfire engineering team, supporting core platform enhancements and maintenance.
Design, implement, and optimize high performance C#/.NET services, frameworks, and integration components.
Work on event-driven, multi-threaded, and distributed system patterns within the Crossfire platform.
Troubleshoot and resolve complex bugs, performance bottlenecks, and reliability issues across the system.
Contribute to architectural improvements, refactoring efforts, and modernization of legacy components.
Collaborate with product owners, architects, and QA to ensure high-quality releases and technical consistency.
Develop clear technical documentation for system components, APIs, interfaces, and deployment processes.
Mentor team members and provide technical leadership where necessary.

Required Qualifications:
7-10 years of professional software engineering experience.
Expert-level proficiency in C#, .NET Framework/.NET Core, and advanced debugging techniques.

Strong experience with:
Multi-threaded programming
Event-driven or message-based architectures
Windows services and system-level programming
Networking protocols, sockets, and real-time communications
Copilot AI and different models
Proven ability to quickly understand and contribute to large, existing codebases.

Equal Opportunity Employer / Disabled / Protected Veterans

The Know Your Rights poster is available here:
-06/22-088_EEOC_KnowYourRights6.12.pdf

The pay transparency policy is available here:
- transp_%20English_formattedESQA508c.pdf

For temporary assignments lasting 13 weeks or longer, the Company is pleased to offer major medical, dental, vision, 401k and any statutory sick pay where required.

We are committed to working with and providing reasonable accommodations to individuals with disabilities. If you need a reasonable accommodation for any part of the employment process, please contact your staffing representative who will reach out to our HR team.

AllSTEM Connections participates in the E-Verify program in certain locations as required by law. Learn more about the E-Verify program.
verify.uscis.gov/web/media/resourcesContents/E - Verify_Participation_Poster_ES.pdf

We also consider for employment qualified applicants regardless of criminal histories, consistent with legal requirements, including, if applicable, the City of Los Angeles’ Fair Chance Initiative for Hiring Ordinance. Pursuant to applicable state and municipal Fair Chance Laws and Ordinances, we will consider for employment-qualified applicants with arrest and conviction records, including, if applicable, the San Francisco Fair Chance Ordinance. For Los Angeles, CA applicants: Qualified applications with arrest or conviction records will be considered for employment in accordance with the Los Angeles County Fair Chance Ordinance for Employers and the California Fair Chance Act.

#3412

Company Description

Guiding Principles and Core Values: UP HIRE
Understanding Matters.
We actively listen to each other, our STEM professionals, and customers. We take the time to understand their needs to make the best connections in the industry.

People Matter.
People are at the center of our company. All decisions we make are in the best of interest of our employees, co-workers, communities, candidates and customers.

Honesty Matters.
We conduct our business with integrity and DO the right things. We ARE trustworthy partners WHO stand behind our work and people.

Innovation Matters.
We are disciplined in bringing forward new thought and solutions that guide the industry and grow our company. Continued growth secures sustainability that provides solid careers for our employees, stability for our STEM professionals, and reliability to our customers.

Relationships Matter.
We take personal responsibility for all relationships with our employees, co-workers, STEM professionals and customers. Courtesy, dignity and respect EQUAL high performance results.

Everything Matters.
We hold ourselves accountable to perform with the upmost of professionalism, attention to detail, and highest standard of service. We hit our targets and do what we say we will do.

Company Description

Guiding Principles and Core Values: UP HIRE\r\nUnderstanding Matters.\r\nWe actively listen to each other, our STEM professionals, and customers. We take the time to understand their needs to make the best connections in the industry.\r\n\r\nPeople Matter.\r\nPeople are at the center of our company. All decisions we make are in the best of interest of our employees, co-workers, communities, candidates and customers.\r\n\r\nHonesty Matters.\r\nWe conduct our business with integrity and DO the right things. We ARE trustworthy partners WHO stand behind our work and people.\r\n\r\nInnovation Matters.\r\nWe are disciplined in bringing forward new thought and solutions that guide the industry and grow our company. Continued growth secures sustainability that provides solid careers for our employees, stability for our STEM professionals, and reliability to our customers.\r\n\r\nRelationships Matter.\r\nWe take personal responsibility for all relationships with our employees, co-workers, STEM professionals and customers. Courtesy, dignity and respect EQUAL high performance results.\r\n\r\nEverything Matters.\r\nWe hold ourselves accountable to perform with the upmost of professionalism, attention to detail, and highest standard of service. We hit our targets and do what we say we will do.