Java Backend Developer for AI Systems
Join OpenTrain as a remote Java backend developer building backend components that support AI systems; 20+ hours/week, contractor role paying $30–$80/hr. Work through OpenTrain to contribute high-quality input that helps shape modern AI behavior.
Coding & Software
$30–$80/hr
Compensation
Worldwide
Eligibility
Entry
Experience
Jun 30, 2026
Posted
Open worldwide
About OpenTrain
OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. We help people discover projects, consolidate opportunities, and build a unified AI-training portfolio they control so they can grow a durable freelance career in the fast-moving AI industry.
Why AI training work matters
AI systems learn from human-created examples, reviews, and code. Contributors—software engineers, annotators, and evaluators—provide the real-world inputs that shape how models behave. This work is often remote, flexible, and accessible to people with focused technical skills.
The role
OpenTrain is recruiting for a Java Developer to design, build, and maintain backend components used in AI systems. This contractor, part-time role focuses on producing high-quality, secure, and scalable backend services that support model training, evaluation, and production workflows.
- Employment type: Contractor, part-time
- Location: Remote (worldwide)
- Time commitment: 20+ hours/week
- Language: English
What you'll do
- Design, develop, and maintain backend components using Java and the Spring ecosystem.
- Implement secure, scalable software aligned with business objectives.
- Collaborate with architects, product owners, and QA engineers on cross-functional teams.
- Participate in code reviews and contribute to continuous improvement efforts.
- Troubleshoot, debug, and optimize backend processes for performance and reliability.
- Write clean, well-documented code that follows industry standards.
- Communicate clearly in writing and verbally to align with customer vision and team goals.
Requirements
Candidates must meet the substantive technical requirements listed below. The posting lists the experience level as entry level, but the technical requirements expect strong demonstrated ability in backend Java development.
- Expert-level proficiency in Java programming and backend development.
- Strong hands-on experience with Spring and related frameworks.
- Solid understanding of RESTful services, microservices architecture, and API design.
- Proven ability to work independently in a remote team setting.
- Excellent written and verbal communication skills.
- Demonstrated track record of delivering complex backend solutions for enterprise environments.
- Strong problem-solving skills and attention to detail.
Helpful background (not required)
- Experience integrating Java applications with modern DevOps tools and cloud platforms.
- Background in performance tuning and optimization for high-traffic systems.
- Prior experience working on distributed, agile teams for global customers.
Pay, schedule, and logistics
This is a remote contractor role requiring 20+ hours per week. The project pays between $30 and $80 USD per hour. You will be expected to deliver production-quality backend code and participate in distributed team processes.
- Pay: $30–$80 USD per hour (PAY_PER_HOUR)
- Hours: 20+ hours/week (part-time)
- Contractor engagement; remote work
How hiring works and next steps
Apply through OpenTrain to submit your profile, experience, and examples of relevant Java backend work. Candidates who match the requirements may be invited to interview or to complete a technical evaluation. OpenTrain helps you track applications and build a portfolio of AI training and development projects.
- Prepare examples of Java/Spring projects and be ready to discuss architecture and performance optimizations.
- Expect a technical evaluation or code review as part of the screening process.