Backend Java Developer for AI Training Systems

About OpenTrain

OpenTrain AI is the hiring and contracting organization for this role. OpenTrain helps people build careers in AI training and data labeling by connecting their skills with cutting-edge projects, supporting professional profiles, and making it easier to apply and grow over time.

As an OpenTrain contractor, you will contribute your backend engineering expertise to systems that support the people and workflows behind modern AI development. Creating an OpenTrain account is free.

• Remote contractor opportunity
• Part-time engagement of 20+ hours per week
• Hourly pay of $60 to $110 USD
• Open to candidates in the listed eligible countries
• English-language role

About AI Training Work

AI training is the human side of building artificial intelligence. People create, review, and evaluate the data, software, and model outputs that help AI systems become more capable, reliable, and useful.

Backend engineers play an important role in this growing field by building dependable services and infrastructure for AI-focused applications. Your work can help support scalable systems used in data-intensive and AI training environments.

• Contribute to the rapidly growing AI training industry
• Apply professional software engineering judgment to AI-focused systems
• Work remotely with flexible contractor scheduling

The Role

OpenTrain is recruiting a Backend Java Developer to design, build, and improve backend systems that support next-generation AI training work. The role centers on expert Java programming, hands-on Spring Boot development, microservices architecture, code quality, technical documentation, and dependable system performance.

This opportunity is listed at the entry level, while the role requirements call for expert Java proficiency and substantial backend engineering capability. Prior AI experience is not required. The primary focus is applying strong backend expertise carefully to AI training systems.

• Core technologies: Java and Spring Boot
• Focus areas: microservices, REST APIs, scalability, and backend reliability
• Work arrangement: remote contractor and part time
• Time requirement: 20+ hours per week
• Pay range: $60 to $110 USD per hour

What You’ll Do

You will work across the backend development lifecycle, from reviewing technical specifications and architecting solutions to troubleshooting live issues and documenting technical decisions. The work requires careful attention to maintainability, performance, reliability, and security.

• 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 and Qualifications

This role requires strong backend engineering fundamentals and the ability to communicate technical ideas clearly in a remote environment. Candidates should be comfortable making informed implementation decisions, producing maintainable code, and collaborating with distributed teams.

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

Helpful Background

Experience with cloud platforms such as AWS, Azure, or Google Cloud is useful. Background in distributed systems, high-availability systems, AI-driven projects, or data-intensive projects can also help you address the role’s reliability and scale expectations.

AI experience is not required. This role is designed for a backend engineer who can transfer strong Java and systems expertise to AI training applications.

• Familiarity with AWS, Azure, or Google Cloud
• Experience with distributed or high-availability systems
• Prior work on AI-driven or data-intensive projects
• Interest in applying backend engineering to AI training systems

Why Work in AI Training

AI training and data labeling work is one of the fastest-growing ways to work in technology. Contributors help prepare and evaluate the examples, software, and feedback used to improve modern AI systems while gaining experience in an expanding technical field.

OpenTrain supports a durable career path by helping freelancers develop a professional AI training portfolio, discover relevant opportunities, and show credible experience as their skills grow.

• Work remotely with a computer and internet connection
• Contribute to how state-of-the-art AI systems are built
• Build experience in a fast-growing technology industry
• Develop a portfolio around AI training and data-focused work

How to Apply

Create a free OpenTrain account to build your profile and apply for this contractor opportunity. Review the role requirements carefully, highlight your Java and Spring Boot experience, and show how your backend engineering judgment can support scalable AI training systems.

• Create or update your free OpenTrain profile
• Highlight Java, Spring Boot, microservices, and REST API experience
• Include relevant cloud, distributed systems, or data-intensive project experience
• Apply through OpenTrain in minutes