Find a jobRecruiters

Backend Developer (Spain)

Exclusive opportunity

Remote

Backend Developer (Spain)

Anyone AI

Backend Developer (Spain)

Skills

TypescriptPythonGolangJavaC#AIJavascript

1 month ago

Share this opportunity

Share this opportunity to other talents of your network:
✓ Offer them a visibility boost with clients.
✓ Help your contacts find their next job.

Important information


Contract type:

Freelance / Contract

Salary:

$93,600 – $166,400 / year

Location:

Madrid, Spain

Work mode:

Remote

Published on:

15 September 2026

What they need


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

Qualifications:

  • Advanced professional written proficiency in English
  • 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

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

Work Type: Remote

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.

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).

Responsibilities:

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

Expected Outcomes:

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

Other offers great for you!

These companies are also looking for great profiles

LittleBig Connection (part of Mantu)

Développeur Backend Kotlin

Freelance

Lyon, France

Onsite

Skills

MongoDBKotlinSpring BootKubernetesSpring WebFluxHelm

14 days ago

Quick apply

Andema

Développeur backend & Plateforme IA Agentique

450

Freelance

Calais, France

Hybrid

Skills

LLMs / Large language modelsReactPythonragia agentiqueagents ia

6 days ago

Quick apply

Meetshake

Développeur Backend / Middleware TypeScript

Freelance

Brussels, Belgium

Hybrid

Skills

SQL QueriesNodeTypescriptMiddleware integrationDistributed systemsCI/CD

2 days ago

Quick apply

The best place to find your next move

© 2026. All Rights Reserved.

Talents

Find a job

Create a profile

Solutions and tools