LLM Java AI Training Developer

You will combine Java software development with hands-on AI training work. Your work will support large language model training, evaluation, and improvement across code, technical responses, and task-specific datasets.

• Design, develop, and maintain efficient Java and backend code used to train and improve AI models.
• Build modular web applications with scalable architectures.
• Evaluate model responses to user queries across different subject areas using defined quality criteria.
• Rank responses and write clear explanations that show your reasoning and technical judgment.
• Create and maintain datasets for supervised fine-tuning.
• Work 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, and review code and documentation for quality.
• Benchmark model performance and analyze results to support ongoing improvement.

What it pays and takes

This is a remote, part-time contractor role. The listing does not specify a pay rate.

• Time commitment: 20 or more hours per week.
• Location: Worldwide.
• Language: Excellent spoken and written English.
• Experience level: Entry level.
• Required: Proficiency with Java syntax, conventions, and modern coding practices.
• Required: Ability to write clean, organized, correct, and clearly annotated code.
• Required: Strong understanding of readability, security, stability, and testing.
• Required: Ability to assess technical responses against clear criteria and explain decisions.
• Education: Bachelor's or master's degree in engineering or computer science, or equivalent experience.
• Helpful: Software quality assurance and test-planning experience.
• Helpful: Experience with large language models, supervised fine-tuning, reinforcement learning with human feedback, or model evaluation.

How it works

Apply on OpenTrain with your resume, then complete the application on the hiring site.

About AI training work

AI training is the human work behind systems that generate text and code: people create examples, review model responses, and rate quality so models improve. OpenTrain is where contributors find and apply for this work, and strong software skills are valuable when projects require accurate code and careful technical judgment.