Software Engineer (C#) — Internal Tooling (AI 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 full-stack C# engineer to build the data pipelines, annotation systems, and evaluation tooling that leading AI labs depend on every day.

This isn't toy work or proof-of-concept territory. You'll be writing production code that sits at the heart of real AI training and evaluation workflows — the kind of systems that determine how models learn, improve, and get measured.

- Organization: Alignerr

- Type: Hourly Contract

- Location: Remote

- Commitment: 20–40 hours/week

What You'll Do

- Design and build high-performance C# systems that support large-scale AI data pipelines and evaluation workflows

- Develop full-stack tooling and backend services for data annotation, validation, and quality control at scale

- Improve reliability, performance, and correctness across existing C# codebases

- Build robust benchmarking and evaluation harnesses to measure system behavior

- Implement interoperability solutions — such as invoking Python ML models from .NET or wrapping native libraries

- Identify bottlenecks and edge cases, then ship scalable, well-reasoned fixes

- Collaborate with data, research, and engineering teams across model training and evaluation workflows





- Participate in synchronous design reviews to iterate on architecture and implementation decisions

Who You Are

- 3–5+ years of professional experience writing production-grade C#

- Strong full-stack developer with a solid systems programming foundation

- Experienced in interoperability scenarios — calling Python ML models from .NET, wrapping native libraries, bridging ecosystems

- Proven track record designing benchmarking harnesses and performance evaluation systems

- Clear, precise written and verbal communicator — you can explain technical decisions to mixed audiences

- 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 pipelines, or evaluation systems

- Familiarity with AI/ML workflows, model training, or benchmarking infrastructure

- Experience with distributed systems or developer tooling

- Background working in fast-moving research or AI-adjacent engineering environments

Why Join Us

- Work on real production systems alongside top AI research labs — not toy demos

- Fully remote and adaptable — structure your hours around your best work

- Freelance autonomy with the substance of meaningful, high-stakes engineering

- Make a tangible impact on the infrastructure that shapes how next-generation AI models are built and evaluated

- Potential for ongoing work and contract extension as projects grow

📌 Software Engineer (C#) - Internal Tooling (México)
🏢 Alignerr
📍 México