Remote Senior Backend Engineer (C#) - AI Data Platform

Alignerr; Seattle (WA); On-site; USD 83,000 - 131,000; Full time

Job summary

Alignerr is seeking a Senior Backend Engineer (C#) for an AI data platform. This fully remote hourly contract role offers 20–40 hours per week and focuses on building scalable data pipelines, annotation tooling, and evaluation systems used by AI labs.

You will design and optimize backend systems, APIs, and services, collaborating with research and engineering teams to enable model training and benchmarking in production environments.

Qualifications

• 5+ years building scalable backend services in C#.
• Strong experience with REST and RPC in distributed systems.
• Experience with cloud-native data services and message buses.
• Excellent written and verbal English; remote collaboration.

Responsibilities

• Design, build, and optimize high-performance backend systems in C# supporting AI data pipelines and evaluation workflows.
• Develop backend services and tooling for data annotation, validation, and quality control at scale.
• Build and maintain RESTful APIs and RPC services for inter-service communication.
• Integrate with cloud-native data services and orchestrate workflows via message bus architectures.
• Identify bottlenecks and reliability issues across codebases and implement scalable fixes.
• Collaborate with research and engineering teams to support model training and evaluation workflows.
• Participate in design reviews and iterate on architecture decisions.

Skills

C#

RESTful APIs

RPC

Cloud platforms

Performance optimization

English communication

Tools

Cloud platforms (Azure/AWS)

Microservices

Job description

Alignerr is seeking a Senior Backend Engineer (C#) for an AI data platform. This fully remote hourly contract role offers 20–40 hours per week and focuses on building scalable data pipelines, annotation tooling, and evaluation systems used by AI labs.

You will design and optimize backend systems, APIs, and services, collaborating with research and engineering teams to enable model training and benchmarking in production environments.