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 build and optimize the data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and benchmark frontier models.

This is a fully remote, versátil contract role for an experienced engineer who wants to work on genuinely hard problems at the intersection of software engineering and AI research — without the constraints of a full-time role.

• 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# that power AI data pipelines and evaluation workflows
• Develop backend services and tooling for large-scale data annotation, validation, and quality control
• Build and maintain RESTful APIs and RPC services for reliable inter-service communication




• Integrate with cloud-native data services and orchestrate workflows across message bus architectures
• Improve reliability, performance, and safety across existing production C# codebases
• Collaborate with data, research, and engineering teams to support model training and evaluation workflows
• Identify bottlenecks and edge cases in system behavior and implement scalable, maintainable fixes
• Participate in synchronous design reviews to iterate on system architecture and implementation decisions

Who You Are

• 5+ years of professional experience building scalable backend services in C#
• Strong systems programming background with a deep understanding of performance and reliability trade-offs
• Mastery of modern frameworks for building RESTful APIs and RPC services
• Solid experience integrating with cloud-native data services and message bus architectures
• Native or fluent English speaker with clear written and verbal communication skills
• Self-dir

📌 Senior Backend Engineer (México)
🏢 Alignerr
📍 México