Senior C# Full-Stack Engineer — AI Data & Infrastructure

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 C# Full-Stack Engineer to build and optimize the data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on every day.
This is a fully remote contract role working on real production systems — not toy projects. You'll be embedded in high-impact engineering workflows alongside data, research, and infrastructure teams pushing 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 C# systems that power AI data pipelines and evaluation workflows
Develop full-stack tooling and backend services for large-scale data annotation, validation, and quality control
Improve reliability, performance, and safety across existing production C# codebases
Collaborate with data, research, and engineering teams to support model training and evaluation infrastructure
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
Experienced full-stack developer with a strong systems programming foundation
3–5+ years of professional experience writing production C# code, with familiarity in modern standards and best practices
Strong background in performance optimization, concurrency (threading, atomics), and memory safety
Able to commit 20–40 hours per week consistently
Self-directed and comfortable working autonomously in a remote environment
Nice to Have
Prior experience with data annotation, data quality pipelines, or evaluation systems
Familiarity with AI/ML workflows, model training, or benchmarking infrastructure
Experience with distributed systems or internal developer tooling
Exposure to C++17/C++20 or other systems-level languages
Why Join Us
Work directly with leading AI labs on production systems that shape next-generation models
Fully remote and flexible — structure your work around your life
Freelance autonomy with the depth and impact of meaningful, long-term technical work
Contribute to AI infrastructure that has real, lasting consequences for how models are built and evaluated
Potential for ongoing work and contract extension as new projects launch

Work arrangement
Yes