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

About The Role
What if your C# expertise could directly shape the infrastructure powering the next generation of AI models? We're looking for a Senior C# Full-Stack Engineer to build and optimize the data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve their most advanced models.
This is a fully remote contract role with meaningful technical challenges, flexible hours, and the chance to work at the frontier of AI development — without leaving your home office.
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 production 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 architecture and implementation decisions
Who You Are
Native or fluent English speaker with strong written and verbal communication skills
Experienced full-stack developer with a solid systems programming foundation
3–5+ years of professional experience writing production C# (modern standards preferred)
Deep understanding of performance optimization, concurrency (threading, atomics), and memory safety
Methodical problem-solver who thrives in fast-moving, high-stakes technical environments
Able to commit 20–40 hours per week with reliability and professionalism
Nice to Have
Prior experience with data annotation, data quality pipelines, or evaluation systems
Familiarity with AI/ML workflows, model training, or benchmarking infrastructure
Experience with distributed systems or internal developer tooling
Background working alongside research or data science teams
Why Join Us
Work directly with leading AI research labs on real production systems — not toy projects
Fully remote and flexible — structure your work around your life
Freelance autonomy with the depth and continuity of meaningful, long-term technical work
Make a direct, tangible impact on the AI systems shaping how the world uses technology
Potential for ongoing work and contract extension as new projects launch

Work arrangement
Yes