Senior Backend Engineer (C#) - AI Data Platform
Posted Today by Alignerr
Negotiable
Undetermined
Remote
United Kingdom
Summary: The Senior Backend Engineer (C#) role focuses on designing and building high-performance data pipelines and evaluation systems for AI applications. This fully remote contract position requires collaboration with data, research, and engineering teams to enhance AI model training and evaluation. The ideal candidate will have extensive experience in C# and backend service development, contributing to real production systems. The role offers flexibility and the opportunity for ongoing work in cutting-edge AI infrastructure projects.
Key Responsibilities:
- Design, build, and optimize high-performance backend systems in C# supporting 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 via message bus architectures
- Improve reliability, performance, and safety across existing C# codebases
- Identify bottlenecks and edge cases in data and system behavior, then implement scalable, durable fixes
- Collaborate with data, research, and engineering teams to support model training and evaluation workflows
- Participate in synchronous design reviews to iterate on architecture and implementation decisions
Key Skills:
- 5+ years of professional experience building scalable backend services in C#
- Strong systems programming background with full-stack exposure
- Mastery of modern frameworks for building RESTful APIs and RPC services
- Experienced with cloud-native data services and message bus / event-driven architectures
- Native or fluent English speaker with clear written and verbal communication skills
- Self-directed and reliable — able to commit 20–40 hours per week and deliver consistently
- Sharp eye for performance bottlenecks, edge cases, and system-level failure modes
- Prior experience with data annotation, data quality pipelines, or model evaluation systems (nice to have)
- Familiarity with AI/ML workflows, model training, or benchmarking infrastructure (nice to have)
- Experience with distributed systems, developer tooling, or data orchestration platforms (nice to have)
Salary (Rate): £37.50 hourly
City: undetermined
Country: United Kingdom
Working Arrangements: remote
IR35 Status: undetermined
Seniority Level: undetermined
Industry: IT
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 design and build the high-performance data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve their models. This is a fully remote contract role with meaningful technical scope. You'll work on real production systems — not toy projects — alongside data, research, and engineering teams at the frontier of AI development.
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# supporting 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 via message bus architectures
- Improve reliability, performance, and safety across existing C# codebases
- Identify bottlenecks and edge cases in data and system behavior, then implement scalable, durable fixes
- Collaborate with data, research, and engineering teams to support model training and evaluation workflows
- Participate in synchronous design reviews to iterate on architecture and implementation decisions
Who You Are
- 5+ years of professional experience building scalable backend services in C#
- Strong systems programming background with full-stack exposure
- Mastery of modern frameworks for building RESTful APIs and RPC services
- Experienced with cloud-native data services and message bus / event-driven architectures
- Native or fluent English speaker with clear written and verbal communication skills
- Self-directed and reliable — able to commit 20–40 hours per week and deliver consistently
- Sharp eye for performance bottlenecks, edge cases, and system-level failure modes
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, developer tooling, or data orchestration platforms
Why Join Us
- Work on cutting-edge AI infrastructure projects alongside leading research labs
- Fully remote and flexible — work from anywhere, on a schedule that suits you
- Freelance autonomy with the structure and purpose of high-impact engineering work
- Make a direct, tangible contribution to the systems that shape how AI models are built and evaluated
- Potential for ongoing work and contract extension as new projects launch