Swift/iOS Code Reviewer (QA) — 30–40 hrs/week

About OpenTrain AI

OpenTrain AI is the hiring and contracting organization for this role. OpenTrain is the leading platform for building careers in AI training and data labeling — a place to discover projects, build a profile, and apply quickly. Creating an OpenTrain account is free.

About AI training work

AI training (also called data labeling or human feedback work) is the human side of building intelligent systems. Contributors annotate, review, and validate the examples models learn from — a fast-growing, mostly remote industry with flexible part-time opportunities.

This role focuses on the code side of AI training: your reviews and feedback help ensure the training data and developer outputs are technically correct and reliable, directly shaping how models behave.

The role

We are seeking an experienced Swift/iOS developer to serve as a Code QA / AI Data Trainer. You will review and quality-assure Swift code responses produced during AI training tasks, verifying that implementations match prompts and are technically correct.

This is a contractor, part-time role expected to require 30–40 hours per week for an estimated 3–6 months. The rate is USD $14 per hour. The position is fully remote and open worldwide.

What you'll do

• Review Swift/iOS code submitted in response to training prompts and verify it meets functional and prompt-specific requirements.
• Check technical correctness: compile/run mental models, spot logic errors, API misuse, memory or concurrency issues, and platform-specific pitfalls.
• Evaluate adherence to best practices, Swift conventions, and secure, maintainable code patterns.
• Provide clear, actionable feedback and correction notes to freelance trainers to improve future outputs.
• Document recurring issues and suggest improvements to QA guidelines and checklists used by the project.

Requirements

• Minimum 5 years of real-world Swift/iOS development experience — this is a firm requirement.
• Proven ability to analyze, optimize, and review Swift code with attention to architecture, correctness, and best practices.
• Strong problem-solving skills and a detail-oriented approach to QA work.
• English proficiency at CEFR B2 or higher; when you apply, state your English proficiency level (CEFR).
• Ability to work independently and reliably with minimal supervision and to adapt quickly to new tools or guidelines.
• Excellent written communication and constructive feedback skills.
• Familiarity with AI model training concepts and how code outputs are used in labeling/training is a plus; experience on other AI data platforms is beneficial but not required.

Who should apply

Experienced Swift/iOS engineers who enjoy code review and care about high-quality outputs should apply. This role fits developers who want steady, project-focused remote work and who can commit to the weekly hours and contract duration.

If you have prior QA or annotation experience in AI training, that will help but is not mandatory — what matters most is deep Swift expertise and clear English communication.

How to apply

Apply through your OpenTrain profile. Include a brief resume, links to sample code or a GitHub repo, your typical weekly availability, and your earliest start date.

Important: state your English proficiency level using the CEFR scale (for example: B2, C1). We require B2 minimum.

You will be contracted as a part-time contractor at USD $14/hr for an expected 3–6 month engagement with a typical weekly commitment of 30–40 hours.