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

Alignerr is seeking a Senior C# Full-Stack Engineer to contribute to the infrastructure powering AI development. The role focuses on building and optimizing data pipelines, annotation tooling, and evaluation systems, collaborating with various teams to ensure high performance and reliability.

Responsibilities:

• Design, build, and optimize high-performance C# systems supporting 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 C# codebases
• Collaborate 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, production-ready fixes
• Participate in synchronous design and code reviews to iterate on system architecture and implementation decisions

Requirements:

• Native or fluent English speaker with clear written and verbal communication skills
• Experienced full-stack developer with a strong systems programming background
• 3–5+ years of professional experience writing production C# with a focus on modern standards
• Deep understanding of performance optimization, concurrency (threading, atomics), and memory safety
• Self-directed and reliable — able to commit 20–40 hours per week and deliver without hand-holding
• 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
• Background in C++17/C++20 or other systems-level languages