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 high-performance 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 hours. You'll be working on real production systems — not toy projects — alongside data, research, and engineering teams at the frontier of AI development.
Organization: Alignerr
Type: Hourly Contract
Location: Remote
Commitment: 20–40 hours/week
What You'll Do
Design, build, and optimize high-performance backend systems in C# supporting large-scale AI data pipelines and evaluation workflows
Develop backend services and tooling for data annotation, validation, and quality control at scale
Build and maintain RESTful APIs and RPC services for reliable inter-service communication
Integrate with cloud-native data services and orchestrate workflows via message bus architectures
Identify bottlenecks, edge cases, and reliability issues across existing codebases — then implement scalable fixes
Collaborate with research and engineering teams to support model training, benchmarking, and evaluation workflows
Participate in synchronous design reviews and iterate on system architecture decisions
Who You Are
5+ years of professional experience building scalable backend services in C#
Deep command of modern C# frameworks for RESTful APIs and RPC-based inter-service communication
Experienced integrating with cloud-native data services and message bus architectures
Systems-level thinker who can identify performance issues and architect clean, scalable solutions
Clear, concise written and verbal communicator — comfortable working with cross-functional teams
Native or fluent English speaker
Able to commit 20–40 hours per week consistently
Nice to Have
Prior experience with data annotation platforms, data quality systems, or evaluation pipelines
Familiarity with AI/ML workflows, model training, or benchmarking infrastructure
Experience with distributed systems design or developer tooling
Full-stack background with frontend exposure alongside a strong backend foundation
Why Join Us
Work directly on cutting-edge AI projects alongside leading research labs
Fully remote and flexible — work from wherever you do your best work
Freelance autonomy with the structure of meaningful, high-impact engineering work
Contribute to infrastructure that shapes how next-generation AI systems are built and evaluated
Potential for ongoing work and contract extension as new projects launch

Work arrangement
Yes