Senior C# Code Reviewer (Remote Contract)

About OpenTrain

OpenTrain AI is the #1 platform for people building careers in AI training and data labeling. We connect contributors with paid, remote projects that directly shape how next-generation AI systems behave. Creating an OpenTrain account is free.

About AI training and why it matters

AI training (also called data labeling or human feedback work) is the human layer that teaches models to produce useful, safe outputs. Contributors audit, annotate, and evaluate model responses—work that is remote, flexible, and accessible to many technical backgrounds.

This role sits at the intersection of code quality and AI evaluation: your reviews and corrections improve the training data that models learn from, making a direct impact on their correctness and security.

The role

You will review annotator evaluations of AI-generated C# code submissions and act as the final technical arbiter. For every submission you will compile and run the snippet in an isolated container, confirm it follows the prompt, verify functionality, and evaluate performance and security practices against our Project Atlas quality rubric.

You will correct mis-ratings, provide concise, targeted feedback to annotators, and ensure each review meets our structured QA standards. This is a part-time contract role requiring 20+ hours per week, paid at $25/hour.

• Employment type: Contractor, Part-time
• Hours: 20+ hours/week
• Pay: $25 USD per hour
• Work location: 100% remote (worldwide)

What you'll do day-to-day

Execute a hands-on, technical audit for each AI-generated C# code submission and the annotator's review.

Provide clear pass/fail judgments, correct reviewer scores when necessary, and write concise remediation comments so annotators can improve.

• Compile and run code snippets in isolated containers and confirm they meet the prompt requirements.
• Verify correctness, edge-case behavior, and acceptable performance characteristics.
• Check for secure-coding issues (injection, unsafe casts, deserialization flaws, privilege escalation, race conditions).
• Assess concurrency and resource-management concerns (thread safety, TPL, Channels, GC behavior).
• Use unit/integration tests (xUnit/NUnit, Testcontainers) to validate behavior and reproducibility.
• Apply the Project Atlas quality rubric and checklist-based scoring for every review.

Requirements

You must bring deep, hands-on C#/.NET expertise and excellent written English. All requirements below come from the role and will be verified in evaluation steps.

• 7+ years professional experience in C#/.NET development, QA, or code-review roles.
• Expert knowledge of modern C# (versions 10–13) and .NET Core / ASP.NET (Core 6/7/8).
• Strong understanding of CLR internals, memory management, GC tuning, and profiling.
• Proven skills with async/await, LINQ, generics, dependency injection, and concurrency patterns.
• Advanced unit/integration testing experience with xUnit/NUnit/MSTest, Testcontainers, Moq, and coverage tools (Coverlet, dotCover).
• Familiarity with build and toolchains: MSBuild/dotnet CLI, Dockerized builds, and CI/CD pipelines.
• Comfort compiling and executing code in sandboxed/container environments to validate prompt compliance.
• Excellent written English (B2+ CEFR); able to write concise, constructive feedback and mentor annotators.

Nice-to-have

These skills are useful but not required; they will help you succeed faster in the project.

• Experience with profiling tools (dotTrace, dotMemory) and advanced GC tuning.
• Familiarity with OWASP-style threat models and secure-code review checklists.
• Previous exposure to LLM evaluation, RLHF workflows, or other AI/ML labeling projects.
• Comfort using ticketing and QA tools (Jira, Asana) and code-review platforms.

How reviews and feedback work

You will follow a rubric-based workflow (Project Atlas) for every task. Each submission is evaluated for correctness, security, performance, and prompt compliance; when an annotator's rating is incorrect you will adjust the score and add targeted feedback.

Expect to work in short review units (one or more submissions at a time), documenting findings clearly so they can be used as training signals for both annotators and models.

• Deliver concise corrective comments that cite exact issues and recommended fixes.
• Annotator mentoring and quality enforcement are part of the role—focus on clarity and actionability.
• All code execution must occur in isolated containers; never run unreviewed code on your local machine.

Who should apply and next steps

This role is a fit for senior .NET engineers who enjoy code review, teaching others through feedback, and working at the interface of software engineering and AI training.

To apply, create an OpenTrain account (free) and submit your profile with relevant C# experience. Qualified candidates will complete a short technical validation to demonstrate compilation, sandboxed execution, and review writing skills.

• Ideal if you like part-time remote work and structured QA processes.
• You will be assessed on both technical correctness and the clarity of your written feedback.