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# Senior .NET Modernization Engineer (Remote - USA)

- **Company:** Brain Trust, LLC
- **Location:** Austin, TX, United States
- **Experience:** Expert
- **Salary:** $208,000.0 - $249,600.0
- **Contract:** Temporary contract
- **Skills:** .NET Framework, Amazon Web Services, C Sharp (Programming Language), Software as a Service, Continuous Integration, Cursor, Github, MongoDB, Node.Js, Microsoft Copilot, TypeScript, Datadog, Data Logging, Claude Code, AI Coding Agents, Docker, Jenkins
- **Published:** October 29, 2026
- **Apply:** https://www.indeed.com/viewjob?jk=ef9d9b58ddaf1f5e

## About the Role

* Significant professional C#/.NET experience (roughly 8-10+ years), including real depth in .NET Framework 4.x.
 * Has led or done much of the hands-on work on a .NET Framework to modern .NET migration of a large system while it stayed in production. A greenfield rewrite or a small-app port isn't the same thing.
 * Solid MongoDB experience, including working through driver and server version upgrades.
 * Comfortable in large, under-tested legacy codebases. You know how to add regression safety before changing behavior.
 * Uses AI coding tools every day (e.g., Claude Code, Cursor, Copilot) and backs their output with tests, review, and evidence.
 * Strong communicator who can work independently inside a product team, gather requirements, and explain technical risk to non-engineers.

Nice to Have

 * Experience with .NET Standard 2.0 / multi-targeting strategies for shared libraries during incremental migrations.
 * HR tech, benefits, payroll, leave and absence, or other rules-heavy business domains.
 * Multi-tenant SaaS and keeping each customer's data isolated.
 * AWS, Docker, CI/CD (GitHub Actions, Jenkins), and structured logging or observability (e.g., Datadog).
 * A second modern stack such as TypeScript/Node.js.