Competitive Programming Checker Developer

About OpenTrain

OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. We help freelancers discover projects, consolidate proof of work, and grow a durable portfolio to show technical experience across the industry.

Work with OpenTrain to connect your competitive-programming skills to meaningful AI training tasks — all remote and designed for flexible, portfolio-driven freelance careers.

Why AI Training Matters

AI training (data labeling/annotation) is the human foundation behind modern models. Contributors prepare, verify, and refine examples that guide model behavior across code, language, images, and audio.

This role lets you apply competitive-programming expertise directly to model training: designing problems, validating many possible correct outputs, and building the test suites that teach models how solutions should be judged.

The Role

You will develop reinforcement-learning-style validation environments for challenging coding problems. The core of the job is designing problems, writing reference solutions, and implementing robust C++ checkers that accept multiple valid outputs and catch subtle edge cases.

This is a remote contractor, part-time role expected to take 20+ hours per week, paid hourly between $45 and $65 (USD).

• Job type: Remote contractor, part-time
• Expected time commitment: 20+ hours/week
• Pay: $45–$65 per hour (USD)

What You’ll Do

Build end-to-end validation artifacts that let AI systems and human participants be evaluated reliably. Your day-to-day work balances creative problem design with precise, defensive coding and clear documentation.

• Design custom competitive programming problems and clearly specify constraints and expected behavior.
• Write reference solutions that demonstrate correct approaches and boundary handling.
• Implement C++ checkers that validate outputs when multiple answers are possible.
• Create robust test suites that probe edge cases and stress tricky constraints.
• Document checker logic and explain subtle failure modes and ambiguous cases.
• Provide feedback and iterate on test cases and checker improvements.

Requirements

We need engineers with strong competitive-programming backgrounds who can think both like a problem setter and a cautious validator. Read the requirements carefully — they reflect the technical scope of the work.

• Strong competitive programming problem-solving and analysis skills.
• Advanced C++ proficiency for checker development and maintainable validation code.
• Experience writing reference solutions and validating outputs with multiple valid answers.
• Familiarity with problem setting, testing, or checker work on major competitive programming platforms is preferred.
• Clear technical communication and careful reasoning about edge cases.
• Comfort working independently in a remote, collaborative environment.

Who Should Apply

This role suits early-career or transitioning engineers with real competitive-programming experience who want to apply those skills to AI training. If you enjoy problem design, writing rigorous test cases, and building defensible checkers in C++, you’ll fit well.

• Entry-level to early-career competitive programmers with demonstrable problem-setting or checker experience.
• Engineers who value correctness, reproducible validation, and clear documentation.
• Anyone looking for flexible, remote contract work that builds a visible portfolio in AI training.

How It Works

Apply through OpenTrain and include examples of competitive problems you’ve set, reference solutions, or checker code if available. We evaluate applicants on problem-design thinking, C++ code quality, and attention to edge cases.

Successful contributors join as contractors and are paid hourly for work producing checkers, test suites, and documentation. OpenTrain helps you consolidate this work into a portfolio that grows your reputation in AI training.

• Languages: English
• Worldwide applicants accepted
• Employment: Contractor, part-time