Senior C# Full-Stack Engineer — AI Data & Infrastructure

Senior C# Full-Stack Engineer — AI Data & Infrastructure

About the Role

What if your C# expertise could directly shape the systems that power the world's most advanced AI models? We're looking for a Senior C# Full-Stack Engineer to design and build the data pipelines, annotation tooling, and evaluation infrastructure that leading AI labs depend on to train and improve next-generation AI.

This is a fully remote contract role working on real production systems — not toy problems. You'll collaborate with data, research, and engineering teams at the frontier of AI development, solving genuinely hard infrastructure and systems challenges at scale.

• 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 bottlenecks and edge cases in data and system behavior, and implement scalable, production-ready fixes
• Participate in synchronous design reviews to iterate on system architecture and implementation decisions

Who You Are

• Full-stack developer with a strong systems programming background and deep C# expertise
• 3–5+ years of professional experience writing production C# code with a focus on modern standards
• Solid understanding of performance optimization, concurrency (threading, atomics), and memory safety
• Clear and precise written and verbal communicator — you can articulate technical decisions confidently
• Native or fluent English speaker
• Available to commit 20–40 hours per week consistently

Nice to Have

• Prior experience with data annotation, data quality, or evaluation systems
• Familiarity with AI/ML workflows, model training pipelines, or benchmarking systems
• Experience with distributed systems or developer tooling
• Background working with or alongside research teams in fast-moving technical environments

Why Join Us

• Work directly on cutting-edge AI systems used by leading research labs
• Fully remote and flexible — structure your work around your life
• Freelance autonomy with the depth and impact of high-stakes engineering work
• Collaborate with world-class engineers and researchers on problems that actually matter
• Potential for ongoing work and contract extension as projects evolve and expand