Senior Backend Engineer (C#) - AI Data Platform

Senior Backend Engineer (C#) — AI Data Platform
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 Backend 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.
This is a fully remote contract role with flexible scheduling — and the work is anything but routine. You'll be embedded in real production systems, solving hard engineering problems at the intersection of scale, performance, and AI.
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 used in production AI systems
Collaborate closely with data, research, and engineering teams to support model training and evaluation workflows
Identify bottlenecks and edge cases in data and system behavior — then implement scalable, elegant 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 mastery of modern frameworks for RESTful APIs and RPC services for inter-service communication
Experienced integrating with cloud-native data services and orchestrating workflows via message bus architectures
Self-directed and reliable — you can commit to 20–40 hours per week and deliver without hand-holding
Nice to Have
Prior experience with data annotation, data quality pipelines, or evaluation systems
Familiarity with AI/ML workflows, model training, or benchmarking pipelines
Experience with distributed systems design or developer tooling
Why Join Us
Work on cutting-edge AI infrastructure alongside world-class research labs
Fully remote and flexible — work on your own schedule from anywhere
Freelance autonomy with the substance of genuinely high-impact engineering work
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

Work arrangement
Yes