Backend Developer - AI Data Services

About the Role

What if your C# expertise could directly shape the infrastructure powering the next generation of AI? We're looking for a senior-level full-stack engineer to design and build the data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve their models.

What You'll Do

• Design, build, and optimize high-performance C# systems supporting large-scale AI data pipelines and evaluation workflows
• Develop full-stack backend tooling and services for data annotation, validation, and quality control
• Improve the reliability, performance, and safety of existing C# codebases
• Collaborate with research and engineering teams to support model training and evaluation infrastructure
• Identify bottlenecks and edge cases across data and system behavior, then 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 clear written and verbal communication skills
• Experienced full-stack developer with a strong systems programming background
• 5+ years of professional experience writing production-grade C#
• Skilled in data modeling and database access using ORM frameworks or micro-ORMs for high-performance SQL interactions
• Proven experience building secure, well-documented endpoints for data access and manipulation
• Able to commit reliably to 20–40 hours per week

Nice to Have

• Prior experience with data annotation, data quality systems, or evaluation pipelines
• Familiarity with AI/ML workflows, model training, or benchmarking infrastructure
• Experience with distributed systems or developer tooling

Why Join Us

• Work on cutting-edge AI infrastructure projects alongside leading research labs
• Fully remote and flexible — work when and where it suits you
• Freelance autonomy with the structure and substance of high-impact, meaningful work
• Make a direct, tangible contribution to the systems that shape how AI learns and improves
• Potential for ongoing work and contract extension as new projects launch