Senior Backend Engineer (C#) - AI Data Platform
About this role
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, flexible 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-directed and dependable — you can commit 20–40 hours per week and deliver without hand-holding Nice to Have - Prior experience with data annotation, data quality pipelines, or model evaluation systems - Familiarity with AI/ML workflows, model training, or benchmarking infrastructure - Experience with distributed systems design or developer tooling - Background in full-stack development alongside strong backend fundamentals Why Join Us - Work on real production systems used by leading AI research labs — this is high-impact engineering, not toy projects - Fully remote and async-friendly — work when and where you do your best thinking - Freelance autonomy with the structure of meaningful, ongoing technical work - Collaborate with engineers and researchers at the cutting edge of AI development - Potential for ongoing contract extension as projects scale and new work launches
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