Backend Developer - AI Data Services

Labelbox; Remote; GBP 80,000 - 100,000; Part time

Job summary

A leading AI solutions provider is seeking a Senior C# Full-Stack Engineer to develop high-performance systems for AI data management. The role includes building tools and services for data annotation and collaborating with interdisciplinary teams. The ideal candidate must have over 5 years of experience in C#, strong full-stack development skills, and the capacity to commit 20–40 hours per week. This is a competitive hourly contract role offered remotely from the United Kingdom.

Qualifications

• 5+ years of professional experience writing production C#.
• Strong systems programming background.
• Ability to commit 20–40 hours per week.

Responsibilities

• Design, build, and optimize high-performance systems in C#.
• Develop full-stack tooling and backend services for data annotation.
• Collaborate with teams to support model training workflows.

Skills

Fluent English

Full-stack development experience

C# programming

Data modeling

Database access using ORM

Clear communication skills

Job description

About the Job

Alignerr connects top technical experts with leading AI labs to build, evaluate, and improve next-generation models. We work on real production systems and high-impact research workflows across data, tooling, and infrastructure.

Position

Senior C# Full-Stack Engineer — AI Data & Infrastructure

Type: Contract, Remote | Commitment: 20–40 hours/week | Compensation: Competitive, hourly (based on experience)

Role Responsibilities

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

Qualifications

Must-Have

• Native or fluent English speaker
• Full-stack developer experience with a strong systems programming background
• 5+ years of professional experience writing production C#
• Strong skills in data modeling and database access using ORM frameworks or micro-ORMs for high-performance SQL interactions
• Experience building secure, documented endpoints for data access and manipulation
• Clear written and verbal communication skills
• Ability to commit 20–40 hours per week

Preferred

• Prior experience with data annotation, data quality, or evaluation systems
• Familiarity with AI/ML workflows, model training, or benchmarking pipelines
• Experience with distributed systems or developer tooling

Application Process

• Submit your resume
• Complete a short technical screening
• Project matching and onboarding