Senior C#​/.NET Engineer

About Codeworks

Codeworks, an LRS Company, has over 25 years of experience serving Fortune 500-1000 companies in Wisconsin as well as our client's national locations. Our recruiting team excels at evaluating, advising, and connecting IT professionals with new opportunities that will satisfy their expectations regarding income and opportunity for growth. At Codeworks, we're committed to diversity, equity, and inclusion in our workforce and beyond.

We believe in equal opportunities and value the unique perspectives that every individual brings to our team. Join us in creating an inclusive, innovative, and collaborative workplace where your talents can thrive.

Location: Westford, MA (Onsite T/W/Th; no relocation — local candidates only)

Type: Contract with high intent to convert

Work Authorization: W2 only (no C2C). Must be authorized to work in the U.S. now and in the future; sponsorship not available.

We’re seeking a hands-on Sr. C#/.NET Engineer to accelerate modernization of our client's security integration platform, a long-lived, mission-critical system that supports 1,000+ IoT clients and devices globally. You’ll work deep in the server platform (not UI/web), tackling multi-threaded, event-driven, cross-process communication at scale, improving stability and performance, and guiding architectural evolution (e.g., moving from singleton services to active-active).

This role is not a fit for predominantly UI/Web/ASP.NET profiles or engineers who haven’t built/owned multithreaded server architectures. (You may be able to write apps/UI, but the core need is backend/server concurrency and real-time systems.)

If you thrive in complex, high-uptime systems and can ramp quickly in a large codebase, you’ll feel right at home here.

• Serve as a principal-level contributor within a small, senior team (