Software Engineer (C#) - Internal Tooling

Software Engineer (C#) — Internal Tooling (AI Infrastructure)

About the Role

What if your C# skills could directly shape the systems powering some of the most advanced AI models in the world? We're looking for a Senior C# Full-Stack Engineer to build and optimize the data pipelines, annotation tooling, and evaluation infrastructure that leading AI labs depend on every day.

This is a fully remote contract role with flexible hours. You'll work on real production systems — not toy projects — alongside data, research, and engineering teams pushing 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 large-scale AI data pipelines and evaluation workflows
• Develop full-stack tooling and backend services for data annotation, validation, and quality control
• Improve reliability, performance, and safety across production C# codebases
• Collaborate with data, research, and engineering teams to support model training and evaluation
• Identify and resolve bottlenecks and edge cases in data and system behavior with scalable, well-reasoned solutions
• Participate in synchronous design reviews to iterate on architecture and implementation decisions

Who You Are

• Native or fluent English speaker with clear written and verbal communication skills
• Full-stack developer with a strong systems programming background
• 3–5+ years of professional experience writing production-grade C#
• Experienced with interoperability scenarios — such as invoking Python ML models from .NET or wrapping native libraries
• Proven ability to design robust benchmarking and evaluation harnesses
• Able to commit 20–40 hours per week reliably

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

Why Join Us

• Work on cutting-edge AI infrastructure alongside leading research labs
• Fully remote and async-friendly — work from anywhere, on a schedule that suits you
• Freelance autonomy with the substance of high-impact, production-level engineering 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