Staff Ruby Engineer (Contractor, Remote)

About OpenTrain

OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. The platform helps freelancers discover projects, consolidate proof of work, and grow a lasting AI training portfolio — creating a single place to manage your contributions across the industry.

Creating an OpenTrain account is free and designed to help you show credible experience and discover roles that match your skills.

Why AI training work matters

AI training (also called data labeling or human feedback work) is the human side of building modern AI. Engineers and annotators provide the examples, reviews, and real-world input that shape how models behave.

This work is often 100% remote, highly flexible, and accessible to people with strong domain skills. Contributing here lets you be on the cutting edge of AI while building a portfolio of real projects.

The role

Micro1 is recruiting a Staff Ruby Engineer on a contractor, part-time basis to help train next‑generation AI systems with high-quality engineering input. You will design scalable Ruby and Ruby on Rails systems, lead API design, optimize databases and performance, and mentor engineers.

This is a contractor role expected to commit 20+ hours per week. The project accepts applications worldwide and requires English (en). No prior AI experience is required; the screening focuses on technical depth, clear communication, and the ability to follow project guidelines.

• Employment type: Contractor, Part-time
• Time requirement: 20+ hours/week
• Languages: English required
• Worldwide applicants accepted

What you'll do

You will be a technical leader on engineering-focused annotation and evaluation work. Tasks combine hands-on development, architecture decisions, and mentorship.

• Design and architect scalable, maintainable Ruby and Ruby on Rails systems
• Develop and optimize database schemas and queries for performance and reliability
• Lead API design and implementation for service-oriented architectures
• Analyze application bottlenecks and drive performance improvements
• Mentor and guide engineers while promoting code quality and technical growth
• Establish coding standards, best practices, and design principles
• Collaborate with cross-functional teams to translate business needs into technical solutions

Requirements

The project requires deep, demonstrable expertise in Ruby and Ruby on Rails along with strong systems and database skills. All substantive requirements below come from the role description.

• Expert-level Ruby and Ruby on Rails proficiency
• Strong system design and architecture experience
• Database modeling, optimization, and management skills
• Performance profiling and tuning experience for web applications
• Hands-on API design and service-oriented systems experience
• Technical leadership and mentorship experience
• Commitment to automated testing and high software quality

Helpful background

These skills are not required but may make your application more competitive on complex projects.

• Experience leading complex projects or initiatives
• Experience with distributed systems and microservices
• Familiarity with DevOps practices and cloud platforms

Compensation and screening

Pay is listed per hour in USD. The input lists an hourlyRate of 90 and an hourly range of $30–$90/hr; applications will be evaluated through the project's screening process that looks for strong technical background, clear communication, and the ability to follow project guidelines.

• Pay type: Hourly (PAY_PER_HOUR)
• Listed hourly range: $30–$90 USD (hourlyRate field shows $90)

Who should apply

This opportunity is a strong fit for experienced Ruby/Rails engineers who want part-time contractor work that contributes to AI training projects. Note: the listing's experienceLevel field is set to 'Entry level' in metadata, but the role text and requirements call for expert-level Ruby/Rails proficiency and technical leadership.

• Engineers who enjoy technical leadership, mentoring, and system design
• Developers comfortable with performance optimization, databases, and APIs
• Freelancers seeking flexible, remote, part-time contractor work

How to apply

To apply, create a free OpenTrain account, complete your profile to show relevant Ruby/Rails experience, and submit your application for the Micro1 Staff Ruby Engineer contractor role. The screening process evaluates technical depth, communication, and adherence to project guidelines.