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This is a fully remote position, open to candidates based in Spain.

Pay: $50-$100/hr

Role Title: Senior Software Engineer

Role Type: Contractor (~15 hrs a week)

Location: Remote

the company is selecting Software Engineers to support a customer's innovative project. In this role, you'll apply your expertise to help train next-generation AI systems. Your work will shape how models learn, reason, and perform through high-quality, real-world input. No prior experience in AI is required - your domain knowledge is what matters.

As an expert you will be creating Reinforcement Learning Environments which test and AI model's ability to solve complex software engineering problems related to fixing code, creating features, refactoring code and optimizing performance. You will be tasked with creating a reproducible environment and golden reference solution for the problem.

Scope of Work




- On this project, you will create realistic, interesting, and extremely challenging coding tasks for frontier AI models using your favourite repositories
- You will design problems that require strong software engineering skills, such as tracking down subtle bugs, building non-trivial features, or improving performance.
- For each task, you will define the problem, build a reproducible environment, and write deterministic verifiers that accept correct solutions across different valid implementations while rejecting incorrect, incomplete, or hard-coded approaches. You will also provide a reference solution showing how the task can be solved.

Preferred Qualifications
- Significant hands-on expertise in at least one of the following: Python3, Java, Rust, Go, C++, or TypeScript.
- Deep understanding of algorithms, data structures, and software engineering principles.
- Proven ability to debug co

📌 Software Engineer (Madrid)
🏢 RemoteJobsOne
📍 Madrid