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Senior Backend Engineer (C#) - AI Data Platform

$50-75/hrRemoteFreelanceCODING

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