Senior .NET Modernization Engineer (Remote) – AI-Driven

Braintrust; United States; Remote; USD 69,000 - 76,000; Full time

Job summary

Braintrust is seeking an experienced engineer to modernize a decade-old .NET/MongoDB-based HR SaaS component. The role emphasizes deep coding, architectural judgment, and hands-on migration work while maintaining production stability.

You will collaborate with product teams, employ AI coding tools responsibly, and plan safe, incremental upgrades across the stack, including from .NET Framework to modern .NET and MongoDB driver upgrades. Remote with US time zones preferred.

Qualifications

• 8–10+ years of professional C#/.NET experience.
• Led or contributed to a .NET Framework to modern .NET migration while in production.
• Solid MongoDB experience and driver/server upgrades.
• Experience with AI coding tools and testing.

Responsibilities

• Analyze legacy .NET Framework systems and plan a safe migration path.
• Architect and sequence upgrade steps with minimal production risk.
• Write and review production code daily, using AI coding agents.
• Develop characterization tests and regression safety checks.
• Coordinate releasing with rollback plans and cross-team communication.
• Collaborate with product and leadership, surface risks early.

Skills

C#/.NET

Migration architecture

Communication

Tools

MongoDB

AI coding tools

Job description

Braintrust is seeking an experienced engineer to modernize a decade-old .NET/MongoDB-based HR SaaS component. The role emphasizes deep coding, architectural judgment, and hands-on migration work while maintaining production stability.

You will collaborate with product teams, employ AI coding tools responsibly, and plan safe, incremental upgrades across the stack, including from .NET Framework to modern .NET and MongoDB driver upgrades. Remote with US time zones preferred.