Java Quality Assurance Lead (Remote, Part-Time)

About OpenTrain

OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. We help people discover AI training projects, build a unified portfolio, and grow a durable freelance career teaching AI.

OpenTrain AI is the hiring and contracting organization for this role and manages onboarding, communication, and quality processes for contributors.

About AI training work

AI training (data labeling, annotation, and human feedback) is the human side of building modern AI systems. Contributors shape how state-of-the-art models behave by reviewing outputs, rating responses, and ensuring technical correctness.

These roles are commonly 100% remote, flexible, and accessible: many projects require strong attention to detail and domain knowledge rather than formal credentials, while specialist tasks pay more for expertise.

The role

OpenTrain is recruiting a Java Quality Assurance Lead to evaluate AI-generated Java code and trainer QA work across Java-focused AI training projects.

This is a part-time contractor role (20+ hours/week), paid at $70/hour (USD). Work is remote but restricted to candidates based in the United States; English fluency for written technical feedback is required.

• Employment type: Contractor, Part-time
• Time requirement: 20+ hours per week
• Pay: $70/hour (USD)
• Location: United States only; English required

What you'll do

As the Java QA Lead you will review AI-generated Java code, judge contributor evaluations, and help maintain high standards for correctness, maintainability, security, test coverage, and clear technical explanation.

• Review Java source, Spring backend snippets, debugging responses, unit tests, architecture explanations, and step-by-step reasoning from contributors.
• Verify compile-time validity and expected runtime behavior; check for correct API usage, object-oriented design, concurrency safety, and exception handling.
• Assess readability, formatting, performance considerations, security concerns, and test coverage (JUnit/Mockito familiarity helpful).
• Spot-check contributor reviews, escalate recurring or systemic issues, and help keep review guidelines and rubrics consistent.
• Maintain Java style guides, FAQs, examples, calibration tasks, honeypots, trackers, and onboarding materials.
• Support onboarding, training, and quality communication for remote Java contributors and implement quality process improvements.

Requirements

Candidates must meet the core technical and communication requirements below. Preferred familiarity and strong pluses are listed separately.

• Strong Java fundamentals: collections, generics, streams, lambdas, exceptions, concurrency, annotations, and JVM behavior.
• Experience reviewing Java code for correctness, readability, maintainability, and security.
• Background in Java development, backend engineering, software QA, code review, or technical mentoring.
• Clear written technical communication in English for feedback and collaboration.
• Familiarity with Spring Boot and common Java tooling such as Maven or Gradle.
• Preferred: experience with JUnit, Mockito, Hibernate/JPA, REST APIs, JDBC, GitHub, Docker, CI/CD, logging, and profiling tools.
• Strong plus: experience leading remote technical contributors or prior work in AI training, rubric-based evaluation, or LLM/code-evaluation workflows.
• Experience level: Intermediate (expectation of solid hands-on engineering and reviewing experience).

Who should apply

Apply if you are an experienced Java developer, backend engineer, technical reviewer, or software QA professional who enjoys mentoring and improving the quality of code at scale.

This role is ideal for contributors who want flexible, part-time remote work that directly shapes how AI tools understand and produce Java code.