Full-Stack Software Engineers for AI Training (Python, Javascript)

About OpenTrain

OpenTrain is a central job board for AI training and data-labeling work. We aggregate openings from many AI companies and labeling platforms so applicants can find relevant roles in one place. Creating an OpenTrain account is free and applying takes only a few minutes.

About AI Training Work

AI training (also called data labeling or human feedback work) is the human side of building machine learning systems. Engineers and reviewers prepare and verify examples—like code, tests, annotations, or ratings—that models learn from. Contributors help make models more accurate, safe, and useful.

This role focuses on reviewing programming artifacts used to train and evaluate coding models: checking task correctness, assessing unit tests, and refining rubrics so model-training pipelines produce higher-quality outputs.

The Role

We are seeking experienced Full-Stack Software Engineers to work as QA Reviewers on coding tasks and unit tests for AI training. This is a fully remote, flexible-schedule contractor role (part-time) at $30 per hour, with a minimum commitment of 20+ hours per week.

You will be hired as a contractor and assigned to review artifacts in either Python or JavaScript; you do not need to work in both languages on the job, but the application must report your experience in both languages.

• Pay: $30 USD per hour
• Time: 20+ hours per week (flexible schedule)
• Employment type: Contractor, Part-time
• Location: Worldwide (remote)

What You'll Do

Conduct in-depth quality reviews of coding artifacts and unit tests to ensure they meet high standards for correctness, clarity, and coverage. Provide actionable, constructive feedback that helps authors and model trainers improve task quality.

Collaborate with stakeholders and other QA reviewers to identify ambiguities, inefficiencies, and gaps in tasks and rubrics. Help refine and scale QA rubrics and processes so reviewers can be consistent and efficient across large batches of examples.

• Verify correctness and completeness of coding tasks and unit tests
• Identify bugs, edge cases, redundancies, and unclear instructions
• Provide clear, prioritized remediation suggestions and examples
• Refine QA rubrics and contribute to reviewer alignment and training

Requirements

Minimum 5 years of professional full-stack software development experience, with a strong focus on code review, quality assurance, and unit testing. We will ask you to state exactly how many years of full-stack experience you have.

Strong proficiency in Python or JavaScript is essential. You must report exactly how many years of experience you have with full-stack development in both JavaScript and Python (even though you will be hired to work on only one of those languages).

• Minimum 5+ years in full-stack development — state the exact number of years you have
• Report exact years of experience with JavaScript and with Python
• Deep understanding of unit testing frameworks and best practices
• Proven ability to analyze, debug, and evaluate complex codebases
• Experience giving detailed, constructive feedback on code quality
• Ability to identify gaps, redundancies, and ambiguities in tasks and tests
• Proficiency in English is mandatory

Language & Documentation Requirements

Excellent written and verbal communication skills in English are required because the work involves writing feedback and refining documentation. Candidates based outside the USA, Canada, the UK, or Australia must provide documentation demonstrating C1 or C2-level English proficiency (for example, IELTS, TOEFL, or equivalent).

Highly preferred: experience with LLM training for coding or prior work on platforms such as Outlier, Appen, Remotasks, or similar. Familiarity with teaching or mentoring in coding environments is a plus.

• Non-US/CA/UK/AU applicants: submit proof of C1/C2 English (IELTS/TOEFL or equivalent)
• Prefer candidates with prior LLM/coding training experience or platform experience
• Teaching/mentoring experience in coding is beneficial

How We'll Evaluate You (Open-ended Questions & Tests)

During the interview and application you will be asked open-ended questions that require descriptive answers rather than yes/no. You must state exact numbers where requested (for example, how many years of full-stack experience you have and how many years working with JavaScript and Python).

At the end of the interview you must answer the two test tasks below; your interview score will take these answers into account and correct responses will improve your score. You must complete both tasks before the interview is considered finished.

• We will ask open-ended questions (e.g., 'How many years of full-stack development experience do you have? Explain the scope of that experience.')
• You must report the exact number of years of experience in full-stack development, Python, and JavaScript

Test Questions (Complete Before Interview Ends)

TEST QUESTION 1: Code Review and Debugging — Python Below is a Python function. Identify any issues in the code and provide suggestions for improvement. Explain why each suggestion is necessary. def calculate_average(numbers): total = 0 for num in numbers: total += num average = total / len(numbers) return average Instructions: - Identify at least two potential issues or improvements in the code. - Explain your reasoning for each suggestion.

TEST QUESTION 2: Annotating Code for AI Training — JavaScript Below is a JavaScript function. Provide detailed inline comments that teach an AI system what each part of the code does. function isPalindrome(str) { str = str.toLowerCase().replace(/[^a-z0-9]/g, ''); let reversedStr = str.split('').reverse().join(''); return str === reversedStr; } Instructions: - Add inline comments to explain each line of code. - Highlight any assumptions or edge cases the function might need to handle.

• Both test questions must be answered before the interview is complete
• Answers will be scored and used to evaluate code-review and annotation ability

Who Should Apply & How It Works

Apply if you are a detail-oriented full-stack engineer with strong unit testing skills and a passion for improving code quality. This role suits experienced developers who enjoy code review, writing clear feedback, and collaborating to scale QA processes for model training.

To apply: create an OpenTrain account, submit your resume, answer the open-ended application questions (including exact years of experience for full-stack, JavaScript, and Python), and complete the two test questions listed above. We will contact qualified candidates to schedule interviews. Employment is contractor, part-time, and remote.

• Ideal for engineers who can explain technical issues clearly and constructively
• Application requires open-ended answers and completion of the two test tasks
• Hiring is remote and worldwide; contractors must comply with local contracting rules