Machine Learning Engineer

Alignerr; España; Remote; EUR 49,000 - 86,000; Full time

Job summary

Alignerr is seeking a Machine Learning Engineer (AI Data Trainer) to help train advanced AI models by producing expert‑level, step‑by‑step reasoning data. The role is fully remote on an hourly contract, offering 10–40 hours per week and flexible scheduling.

You will craft precise reasoning logs and annotated workflows, demonstrating how an expert tackles complex ML and engineering challenges. This is a freelance, asynchronous role with potential for ongoing collaboration.

Qualifications

• Proven background in ML, software engineering, or related technical discipline.
• Ability to articulate complex reasoning and decisions step-by-step.
• Strong independent work and self‑management in asynchronous settings.

Responsibilities

• Construct precise, well‑structured reasoning logs detailing strategy, tools, and decisions at each step.
• Demonstrate expert approaches to ML and engineering challenges to train models.
• Generate annotated workflows showing tool interaction from framing to solution.
• Review AI‑generated reasoning sequences, identify gaps and opportunities for improvement.
• Produce high‑quality training data to improve LLM performance on real‑world tasks.

Skills

Machine Learning

Software Engineering

Analytical thinking

Independent work

Attention to detail

Education

Master's degree or PhD in ML/CS

Job description

Machine Learning Engineer (AI Data Trainer)

About The Role

What if your technical expertise could directly influence how the world's most advanced AI systems learn to reason, plan, and solve problems? We're looking for Machine Learning Engineers to help train cutting-edge AI models by demonstrating expert‑level problem‑solving — step by step, tool by tool, decision by decision.

This isn't a typical ML engineering role. You'll be working at the frontier of AI development, producing the high‑quality reasoning data that teaches large language models how to think like an expert. Your work will have a direct, lasting impact on how AI handles real‑world technical challenges.

This is a fully remote, flexible contract role built for experienced technical professionals who want to contribute to something genuinely significant.

• Organization: Alignerr
• Type: Hourly Contract
• Location: Remote
• Commitment: 10–40 hours/week

What You'll Do

• Construct precise, well‑structured reasoning logs that walk through complex technical problems — capturing your strategy, tool use, and decision‑making at each step
• Demonstrate how an expert approaches sophisticated ML and engineering challenges, producing training data that shows AI models how to reason consistently and reliably
• Generate annotated workflows that illustrate proficient tool interaction, from problem framing through to solution execution
• Review and critically evaluate AI‑generated reasoning sequences, identifying gaps, errors, and opportunities for improvement
• Produce high‑quality training datasets that directly improve LLM performance on real‑world technical tasks

Who You Are

• Professional background in Machine Learning, Software Engineering, or a closely related technical discipline
• Able to clearly articulate complex reasoning processes — you can explain not just what you did, but why, step by step
• Strong critical thinker with the ability to evaluate and refine AI‑generated problem‑solving approaches
• Comfortable working independently and asynchronously with minimal supervision
• Detail‑oriented and methodical — you care about precision and consistency

Nice to Have

• Master's Degree or PhD in Machine Learning, Computer Science, or a related technical field
• Prior experience with data annotation, data quality assurance, or AI evaluation systems
• Familiarity with LLMs, prompt engineering, or AI reasoning frameworks
• Experience documenting technical workflows or writing technical specifications

Why Join Us

• Work directly with leading AI research labs on projects shaping the next generation of AI
• Fully remote and flexible — structure your hours around your life, not the other way around
• Freelance autonomy: choose your own pace, work asynchronously, and collaborate globally
• Gain deep, hands‑on exposure to how frontier LLMs are built and trained
• Contribute to work that genuinely matters — your expertise helps make AI smarter and more reliable for everyone
• Potential for ongoing work and contract extension as new projects launch