LLM Java AI Training Developer

About OpenTrain

OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. We connect skilled contributors with opportunities to help develop modern AI systems, build a professional profile, and grow a lasting portfolio of work.

As an OpenTrain contractor, you can apply your software development expertise to practical AI projects while gaining experience in model evaluation, dataset creation, and human feedback workflows.

• Remote contractor opportunity
• Part-time commitment of 20+ hours per week
• Work with English-language AI training tasks
• Build experience in software development and AI model improvement

About AI Training Work

AI training is the human side of building artificial intelligence. People prepare datasets, review model outputs, write and rank responses, evaluate technical accuracy, and provide feedback that helps AI systems become more useful and reliable.

This role combines programming with hands-on evaluation work. Your technical judgment will help assess whether model-generated code and responses are clear, relevant, secure, stable, and aligned with defined standards.

• Support large language model training and evaluation
• Create data used for supervised fine-tuning
• Contribute to reinforcement learning with human feedback
• Help improve model quality and ethical behavior

The Role

OpenTrain is seeking a Java developer to support large language model training, evaluation, and improvement. You will develop backend components while also reviewing model outputs, creating task-specific datasets, and explaining technical decisions clearly.

The role is suited to someone who can move between software engineering and structured AI data work. It is listed as entry level and requires 20+ hours per week as a part-time contractor.

• Core focus: LLM code and response evaluation
• Employment type: Part-time contractor
• Experience level: Entry level
• Language: English
• Location: Worldwide and remote
• Time requirement: 20+ hours per week

What You'll Do

You will contribute to both the technical implementation and evaluation processes behind AI model improvement. Work should follow explicit quality criteria and support user needs, reliable performance, and ethical model behavior.

• Design, develop, and maintain efficient Java and backend code used to train and optimize AI models.
• Build modular web applications with scalable architectures.
• Conduct model evaluations, benchmark performance, and analyze results for continuous improvement.
• Evaluate and rank responses to user queries across diverse domains using predefined criteria.
• Write clear explanations and rationales that demonstrate sound reasoning and technical judgment.
• Create and maintain high-quality datasets for supervised fine-tuning.
• Collaborate with researchers and annotators on reinforcement learning with human feedback and reward-model improvement.
• Develop evaluation strategies that support user needs and ethical model behavior.
• Create and refine model responses while reviewing code and documentation for quality.

Requirements and Helpful Background

You should be comfortable applying modern Java development practices and evaluating technical work against explicit standards. Clear communication is essential because you will need to explain why code or model responses meet, or fail to meet, quality requirements.

A bachelor's or master's degree in engineering or computer science is required, or equivalent experience. Prior software quality assurance and test-planning experience is useful, as is experience with large language models, supervised fine-tuning, reinforcement learning with human feedback, or model evaluation workflows.

• Strong proficiency with Java syntax, conventions, and backend development
• Experience building modular, scalable web applications
• Ability to produce clean, organized, correct, readable, secure, stable, and clearly annotated code
• Understanding of software testing and quality practices
• Ability to evaluate and rank LLM responses against explicit criteria
• Ability to explain technical judgments clearly
• Understanding of supervised fine-tuning, RLHF, and model evaluation workflows
• Excellent written and spoken English communication
• Bachelor's or master's degree in engineering or computer science, or equivalent experience

Why Build an AI Training Career

AI training and data labeling are among the fastest-growing ways to work in technology. Contributors directly influence how state-of-the-art models write, reason, generate code, and respond to people.

The work can be a flexible way to apply specialized skills remotely. Through OpenTrain, you can develop a profile that reflects your AI training experience and use each project to build a stronger long-term portfolio.

• Work remotely with a computer and internet connection
• Apply software engineering skills to cutting-edge AI development
• Gain practical experience in model evaluation and human feedback
• Build a durable portfolio of AI training work through OpenTrain