Backend Developer - Data Annotation Systems

Alignerr Corp.; Denver (CO); Remote; USD 83,000 - 124,000; Part time

Benefits offered by this job

Remote freelance autonomy

Flexible schedule

Job summary

Alignerr is seeking a Backend Developer for Data Annotation Systems (AI Infrastructure). This remote hourly contract role focuses on building data pipelines, annotation tooling, and evaluation systems that support world-class AI labs.

You’ll work 20–40 hours per week on production-grade Python and full-stack tooling, contributing to scalable, reliable infrastructure. You will collaborate across data, research, and engineering teams to optimize performance, ensure data quality, and support model

Qualifications

• 3–5+ years of production-grade Python experience.
• Experience building asynchronous task queues for long-running jobs.
• Proficient in optimizing database queries for high-read/write workloads.
• Experience serving data via real-time protocols like WebSockets.
• Strong full-stack capabilities with a systems programming background.

Responsibilities

• Design, build, and optimize high-performance Python systems for data pipelines and evaluation workflows.
• Develop full-stack tooling and backend services for data annotation, validation, and quality control at scale.
• Improve reliability, performance, and safety of existing Python codebases.
• Collaborate with data, research, and engineering teams to support model training and evaluation infrastructure.
• Identify bottlenecks and edge cases; implement scalable, production-ready fixes.
• Participate in design reviews to iterate on architecture and implementation decisions.

Skills

Python

Async queues

WebSockets

Full-stack development

Systems programming

Job description

Backend Developer - Data Annotation Systems (AI Infrastructure)

About The Role

What if your Python expertise could directly shape the infrastructure behind the world's most advanced AI models? We're looking for a Senior Python Full-Stack Engineer to design and build the data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve next-generation models.

This is a fully remote, flexible contract role for an experienced engineer who wants to work on real production systems at the cutting edge of AI development - not toy projects, but infrastructure that matters.

• Organization: Alignerr
• Type: Hourly Contract
• Location: Remote
• Commitment: 20-40 hours/week

What You'll Do

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

Who You Are

• Native or fluent English speaker with clear written and verbal communication skills
• Full-stack developer with a strong systems programming background
• 3-5+ years of professional experience writing production-grade Python
• Experienced building asynchronous task queues for long-running background jobs
• Proficient in optimizing database queries for high-read/write workloads and serving data via real-time protocols (e.g., WebSockets)
• Able to commit 20-40 hours per week with reliability and consistency

Nice to Have

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

Why Join Us

• Work directly with leading AI research labs on production-grade, high-impact systems
• Fully remote and flexible - work from anywhere on a schedule that suits you
• Freelance autonomy with the structure and focus of meaningful, substantive engineering work
• Make a direct, tangible contribution to the infrastructure shaping the future of AI
• Potential for ongoing work and contract extension as new projects launch