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 build and optimize 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 with meaningful impact — not toy projects.
- Organization: Alignerr
- Type: Hourly Contract
- Location: Remote
- Commitment: 20–40 hours/week
What You'll Do
- Design, build, and optimize high-performance Python systems supporting large-scale AI data pipelines and evaluation workflows
- Develop full-stack backend tooling and services for data annotation, validation, and quality control at scale
- Build and maintain asynchronous task queues to handle long-running background jobs reliably
- Optimize database queries for high-read/write workloads and serve data via real-time protocols such as WebSockets
- Improve reliability, performance, and robustness across existing Python codebases
- Identify bottlenecks and edge cases in data and system behavior, and implement scalable, production-ready fixes
- Collaborate closely with data, research, and engineering teams to support model training and evaluation workflows
- Participate in synchronous design reviews to iterate on system architecture and implementation decisions
Who You Are
- Strong full-stack developer with a solid systems programming background
- 3–5+ years of professional experience writing production-grade Python
- Experienced building asynchronous task queues for long-running background processing
- Proficient in optimizing database queries for high-throughput applications
- Comfortable working with real-time data protocols (e.g., WebSockets)
- Clear, precise written and verbal communicator
- Able to commit 20–40 hours per week consistently
- Native or fluent English speaker
Nice to Have
- Prior experience with data annotation platforms, data quality systems, or evaluation pipelines
- Familiarity with AI/ML workflows, model training, or benchmarking infrastructure
- Experience with distributed systems or developer tooling
- Background working alongside research or data science teams
Why Join Us
- Work directly with leading AI labs on production systems that matter
- Fully remote and flexible — work from anywhere on a schedule that suits you
- Freelance autonomy with the structure of high-quality, technically challenging work
- Contribute to AI infrastructure that influences how next-generation models are built and evaluated
- Potential for ongoing work and contract extension as new projects launch
Alignerr