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Backend Developer (Spain)

Remote from Spain·Part-time·Added 1 month ago (last checked 26 Oct)

Anyone AI

29 open roles

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Our summary

Salary: US$45 - US$80 an hour
Work mode: Remote from Spain
Contract: Fixed-term, part-time hours
English: Required
Experience: 3+ years

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Skills

Requirements

What we're looking for

3-7 years of professional software engineering experience
Strong proficiency in Python and JavaScript/TypeScript; working knowledge of Java, C#, or Go
Backend or full‑stack development experience in production systems
Experience with testing frameworks (e.g., pytest, Jest, JUnit, xUnit, Go testing)
Proven ability to debug and navigate large, multi‑file codebases
Experience with code reviews, refactoring, and production migrations

Languages

Advanced professional written proficiency in English

The role

Anyone AI is recruiting skilled Backend Developers to work on a project with a leading AI lab.

What you'll do

Contributors will:

Design and implement multi-file coding tasks across bug fixing, feature development, refactoring, and testing
Write clear natural-language specifications and reference implementations
Develop and extend unit and integration test suites
Review peer-generated tasks for correctness, clarity, and realism
Identify edge cases, ambiguities, and potential failure modes
Ensure alignment between specifications, code, and expected outputs

How you'll work

Engagement: Part-time, project-based expert evaluation work

Work Type: Remote

Expected Outcomes

Contributors will design and evaluate realistic software engineering tasks, including bug resolution, feature implementation, refactoring/migration, and test generation. Work includes both creating complex coding scenarios and reviewing peer submissions for quality and accuracy.

High-quality, production-realistic coding tasks
Complete and correct reference implementations
Robust test coverage and validation artifacts
Structured, actionable peer review feedback

Consultant Details

This is a project-based consultant role. Consultants will be paid on a per-project basis; hourly rates are estimates based on anticipated completion time. Consultants control their own schedule, provide their own tools, and may simultaneously provide services to other vendors/employers (subject to those vendors' allowances).

About Anyone AI

Anyone AI is an EdTech company that develops AI-powered educational tools and platforms. Based in San Francisco, the company focuses on leveraging artificial intelligence to enhance learning experiences, offering products that range from AI tutoring systems to adaptive learning technologies. While the company is relatively young, it has established a presence in the AI education space, working with experts across various domains to train and refine its AI models.

Anyone AI has a significant remote-first presence in Spain, hiring experts in fields like mathematics, physics, biology, and software engineering to contribute to AI training and development. The company offers fully remote positions within Spain, making it an attractive option for international professionals seeking flexible work arrangements. With a focus on AI model training and development, Anyone AI provides opportunities for experts to apply their knowledge in a cutting-edge field, though its brand recognition is limited outside of niche AI and EdTech circles.

Industry: EdTech
Employees: 11–50
Headquarters: San Francisco, USA

Good to know if you are moving

All Spain-based roles are fully remote, offering flexibility for international professionals.
The company hires domain experts (e.g., mathematics, physics, biology) to train AI models, making it a unique opportunity for academics and specialists.
As a US-based company, salaries and contracts may be structured under Spanish employment laws, but specifics should be confirmed during the hiring process.
The company is small, so employees may have a direct impact on AI training processes and product development.
Working with a US-based company from Spain may require managing time zone differences, though remote work mitigates this.

All open roles at Anyone AI