Senior Backend Engineer (C#) - AI Data Platform

Senior Backend Engineer (C#) — AI Data Platform

About the Role

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

This is a fully remote contract role with flexible scheduling. You'll work on real production systems alongside data, research, and engineering teams — doing work that has a measurable impact on how AI is built.

• 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 backend services and full-stack tooling 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
• Identify bottlenecks and edge cases in 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
• 5+ years of professional experience building scalable backend services in C#
• Strong systems programming background with full-stack development experience
• Deep expertise in modern frameworks for building RESTful APIs and RPC services for inter-service communication
• Experienced integrating with cloud-native data services and orchestrating workflows via message bus architectures
• Able 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, or benchmarking pipelines
• Experience with distributed systems or developer tooling

Why Join Us

• Work directly on cutting-edge AI infrastructure alongside leading research labs
• Fully remote and flexible — work from wherever you do your best work
• Freelance autonomy with the structure and impact of meaningful, high-stakes engineering
• Contribute to systems that directly influence how next-generation AI models are built and evaluated
• Potential for ongoing work and contract extension as new projects launch