Software Engineer (C#) - Internal Tooling

Alignerr; New York (NY); Remote; USD 83,000 - 138,000; Full time

Job summary

Alignerr is seeking a Software Engineer (C#) for Internal Tooling (AI Infrastructure) to build data pipelines and evaluation tooling in a fully remote contract role. You will work on high-performance systems and integration with AI workflows.

The role requires 3–5+ years of production-grade C#, strong English communication, and the ability to commit 20–40 hours per week, with opportunities for ongoing projects and extension.

Qualifications

• 3–5+ years of production-grade C# experience.
• Experience building data pipelines and AI infrastructure tooling.
• Strong English communication and remote-work discipline.

Responsibilities

• Design, build, and optimize high-performance C# systems for AI data pipelines.
• Develop full-stack tooling and backend services for data annotation and quality control.
• Improve reliability, performance, and safety of existing C# codebases.
• Collaborate with data, research, and engineering teams to support model training.
• Identify bottlenecks in data and system behavior and implement scalable fixes.
• Participate in design reviews and refine architecture with senior engineers.

Skills

C#

Full-stack development

Systems programming

Interoperability with Python

Benchmarking harnesses

Tools

.NET

Job description

Software Engineer (C#) — Internal Tooling (AI Infrastructure)

What if your C# expertise could directly shape the infrastructure powering the world's most advanced AI systems? We're looking for experienced C# full-stack engineers to build and optimize the data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on.

About The Role

This is a fully remote contract role with meaningful technical scope — real production systems, high-impact workflows, and the kind of engineering problems that actually stretch your skills.

• 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 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, and implement scalable, production-ready fixes
• Participate in synchronous design reviews and iterate on system architecture decisions with senior engineers

Who You Are

• Native or fluent English speaker with clear written and verbal communication skills
• Full-stack developer with a strong systems programming background
• 3–5+ years of professional experience writing production-grade C#
• Experienced in interoperability scenarios — such as invoking Python ML models from .NET or wrapping native libraries
• Skilled at designing robust benchmarking and evaluation harnesses
• 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
• Background working directly with or alongside AI research teams

Why Join Us

• Work on cutting-edge AI infrastructure alongside leading research labs
• Fully remote and flexible — work from wherever you do your best engineering
• Freelance autonomy with the structure and consistency of ongoing, meaningful project work
• Tackle genuinely hard technical problems with real-world impact on AI systems at scale
• Potential for ongoing work and contract extension as new projects launch