Senior Backend Engineer (C#) - AI Data Platform

Alignerr Corp.; Denver (CO); Remote; USD 83,000 - 138,000; Part time

Job summary

Alignerr is seeking a Senior Backend Engineer (C#) to design and build data pipelines, annotation tooling, and evaluation systems that support AI labs in training and improving models. This fully remote, flexible contract role requires 20–40 hours per week and collaboration with cross-functional teams.

The ideal candidate has 5+ years of experience in scalable C# backend services, strong RESTful and RPC framework knowledge, and familiarity with cloud-native data services.

Qualifications

• 5+ years of professional experience building scalable backend services in C#.
• Deep expertise in modern frameworks for RESTful APIs and RPC services.
• Experience with cloud-native data services and message bus architectures for workflow orchestration.
• Native or fluent English with clear written and verbal communication skills.
• Self-directed and reliable — able to commit 20–40 hours per week and deliver independently.

Responsibilities

• Design, build, and optimize high-performance C# systems supporting large-scale AI data pipelines and evaluation workflows.
• Develop backend services and tooling for data annotation, validation, and quality control at scale.
• Improve the reliability, performance, and safety of existing C# codebases.
• Collaborate with data, research, and engineering teams to accelerate model training and evaluation.
• Identify and resolve bottlenecks and edge cases across data and system behavior.
• Participate in synchronous design reviews and iterate rapidly on architecture and implementation decisions.

Skills

C#

Backend services

RESTful APIs

RPC services

Cloud-native data services

Message bus architectures

English (fluent)

Self-directed

Job description

Senior Backend Engineer (C#) — AI Data Platform

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 data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve their most advanced models.

About The Role

This is a fully remote, flexible contract role for a seasoned engineer who thrives on solving hard systems problems and wants their work to matter at scale.

• 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 large-scale AI data pipelines and evaluation workflows
• Develop backend services and tooling for data annotation, validation, and quality control at scale
• Improve the reliability, performance, and safety of existing C# codebases
• Collaborate with data, research, and engineering teams to accelerate model training and evaluation
• Identify and resolve bottlenecks and edge cases across data and system behavior
• Participate in synchronous design reviews and iterate rapidly 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 development experience
• Deep expertise in modern frameworks for RESTful APIs and RPC services
• Experienced with cloud-native data services and message bus architectures for workflow orchestration
• 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 independently

Nice to Have

• Prior experience with data annotation platforms, data quality pipelines, or evaluation systems
• Familiarity with AI/ML workflows, model training pipelines, or benchmarking infrastructure
• Experience with distributed systems design or developer tooling
• Background working directly with or alongside AI research teams

Why Join Us

• Work on real production systems used by leading AI research labs — not toy projects
• Fully remote and asynchronous-friendly — work from wherever you do your best work
• Flexible contract structure with meaningful, high-impact technical work
• Collaborate with top engineers and researchers pushing the boundaries of AI
• Potential for ongoing contract extensions as projects grow and new initiatives launch