Software Engineer (C#) - Internal Tooling

Denver

**Software Engineer (C#) --- Internal Tooling (AI Infrastructure)** **About The Role** What if your C# expertise could directly shape the infrastructure powering the next generation of AI? We're looking for experienced full-stack C# engineers to build and improve the systems that leading AI labs depend on --- from data annotation pipelines to evaluation harnesses and quality control tooling. This is a fully remote contract role with flexible commitment. You'll work on real production systems alongside data, research, and engineering teams at the frontier of AI development. * Organization: Alignerr * Type: Hourly Contract * Location: Remote * Commitment: 20--40 hours/week **What You'll Do** * Design, build, and optimize high-performance C# systems supporting AI data pipelines and evaluation workflows * Develop full-stack tooling and backend services for large-scale data annotation, validation, and quality control * Improve reliability, performance, and safety across existing C# codebases * Collaborate with data, research, and engineering teams to support model training and evaluation workflows * Identify and resolve bottlenecks and edge cases in data and system behavior with scalable solutions * Participate in synchronous design reviews to iterate on architecture and implementation decisions * Build and maintain robust benchmarking and performance evaluation harnesses **Who You Are** * 3--5+ years of professional experience writing production-grade C# * Strong full-stack developer background with solid systems programming fundamentals * Expertise in interoperability scenarios --- such as invoking Python ML models from .NET or wrapping native libraries * Experienced designing robust harnesses for benchmarking and evaluating system performance * Native or fluent English speaker with clear written and verbal communication skills * Able to commit 20--40 hours per week with reliability and consistency **Nice to Have** * Prior experience with data annotation, data quality, or evaluation systems * Familiarity with AI/ML workflows, model training, or benchmarking pipelines * Experience with distributed systems or developer tooling * Background working with or alongside research teams in a fast-moving environment **Why Join Us** * Work on cutting-edge AI projects alongside leading research labs * Fully remote and flexible --- work when and where it suits you * Freelance autonomy with the structure of meaningful, high-impact technical work * Build systems that directly influence how next-generation AI models are trained and evaluated * Potential for ongoing work and contract extension as new projects launch