About OpenTrain

OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. It gives contributors one place to discover projects, build a credible professional profile, and apply their skills to opportunities across a fast-growing industry.

As an OpenTrain contractor, you can develop a durable portfolio around specialized technical work while contributing to systems that support how modern AI is built.

• Remote contractor opportunity available worldwide
• Part-time schedule of 20+ hours per week
• Apply through OpenTrain and build an AI training portfolio

About AI Training Work

AI training is the human side of building artificial intelligence. In addition to labeling data and evaluating model outputs, the industry depends on reliable software systems that help organize, process, and support training workflows.

This role applies backend engineering expertise to AI-focused projects. Prior AI experience is not required, making it an opportunity to bring strong software development judgment into a rapidly growing technical field.

• Work connected to next-generation AI training systems
• Use software engineering expertise in a cutting-edge industry
• Contribute remotely with flexible part-time contracting

The Role

OpenTrain is recruiting a Backend Java Developer to build and improve backend systems that support AI training work. You will design and maintain Java and Spring Boot services, architect microservices solutions, and make informed decisions about code quality, performance, reliability, and security.

The role is suited to a backend developer with expert Java proficiency, hands-on Spring Boot experience, and strong knowledge of scalable backend design. You will also contribute through technical documentation, code reviews, troubleshooting, and collaboration with remote teams.

• Role type: Contractor and part time
• Time requirement: 20+ hours per week
• Pay: $60-$110 per hour
• Language: English
• Location: Worldwide and fully remote

What You'll Do

You will take ownership of backend implementation and help ensure that systems are maintainable, scalable, and dependable. The work combines hands-on Java development with architectural thinking, technical communication, and careful quality review.

• Design, develop, and maintain scalable backend systems using Java and Spring Boot
• Architect robust microservices solutions for complex application requirements
• Review technical specifications and deliver high-quality, maintainable code
• Improve application performance, reliability, and security through informed engineering decisions
• Participate in code reviews and provide constructive feedback on implementation quality
• Document technical processes and solutions with clear, concise written communication
• Troubleshoot, debug, and optimize backend systems as needed

Required Skills

The primary focus is backend engineering expertise and the ability to apply it carefully to AI training systems. Candidates should be able to communicate clearly, work attentively, and collaborate effectively in a remote environment.

• Expert proficiency in Java programming
• Hands-on experience with Spring Boot backend development
• Strong understanding of microservices architecture and REST APIs
• Knowledge of data structures and backend engineering best practices
• Ability to write clean, efficient, and maintainable code
• Ability to troubleshoot and optimize backend performance, reliability, and security
• Excellent written and verbal communication
• Careful attention to detail
• Experience collaborating with remote teams

Helpful Background

The following experience is useful but not required. Familiarity with cloud or distributed systems can help you address the reliability and scale expectations of backend work supporting AI-focused applications.

• Exposure to AWS, Azure, or Google Cloud
• Experience with distributed systems
• Background working with high-availability systems
• Prior experience with AI-driven or data-intensive projects

How to Build Your AI Career With OpenTrain

OpenTrain helps people start and grow careers teaching AI, including through technical work that supports training infrastructure and evaluation workflows. Creating an account is free, and your profile can help you present relevant experience, discover matching opportunities, and build a long-term record of AI training work.

Bring your Java and Spring Boot expertise to a remote role connected to the future of AI. Apply through OpenTrain to take the next step.

• Create a free OpenTrain account
• Showcase your backend engineering experience
• Apply to remote AI training opportunities in minutes