Freelance Senior Python Developer / Functional Test Frameworks

Headquarters: Spain
URL: https://mindrift.ai/

Please submit your CV in English and indicate your level of English proficiency.

Mindrift connects specialists with project-based AI opportunities for leading tech companies, focused on testing, evaluating, and improving AI systems. Participation is project‑based as an independent freelance contributor and does not create an employment relationship with Toloka or our clients.

About the Role

This project is suited for a Senior Python developer with deep functional testing experience, strong Linux and Docker skills, the ability to read code across multiple languages with the support of LLMs (e.g., C, Rust, Go) and translate requirements for migration tasks, and confidence using tools like Roo Code or Claude Code to accelerate iterative development.

Key Responsibilities

• Create functional black box tests for large codebases in various source languages
• Create and manage Docker environments to ensure 100% reproducible builds and test execution across different platforms
• Monitor code coverage and configure automated scoring criteria to meet industry benchmark-level standards
• Leverage LLMs (Roo Code, Claude) to accelerate development cycles, automate repetitive tasks, and improve overall code quality

Requirements

• 5+ years of experience as a Software Engineer (primarily Python)
• Deep experience with pytest (fixtures, session-scoped, timeouts) and designing black-box functional tests for CLI tools
• Expert-level Docker skills (reproducible Dockerfiles, user contexts, secure workspaces)
• Strong Linux & Bash scripting skills and comfort debugging inside containers
• Proficiency with modern Python tooling (uv, pyproject.toml, packaging)
• Ability to read and understand with LLM many coding languages (for example C, C++, Rust, or Go) 
• Experience using LLMs (Claude Code, Roo Code, Cursor) to accelerate iterative development and test-case generation
• English language - B2 or higher

Requirements +

• Prior experience with agent evaluation platforms and MCP CLI

Tools and Technologies: Python (pytest, uv, Pillow), Docker, Bash, Git Submodules, C/C++/Rust/Go (reading), Dagger, GitHub Codespaces, LLMs (Claude Code, Roo Code, Cursor), coverage.py, gcov, kcov.

Benefits

What we can offer

• Freelance project-based collaboration via the Mindrift platform (powered by Toloka AI)
• Fully remote and flexible participation — choose when and how much to contribute (20-30 hours per week)
• Task-based compensation, equivalent to up to $80/hour depending on performance and volume
• Opportunity to contribute to innovative AI projects for leading tech companies
• Supportive global community

*Note: Rates vary based on expertise, skills assessment, location, project needs, and other factors. Higher rates may be offered to highly specialized experts. Lower rates may apply during onboarding or non-core project phases. Payment details are shared per project.

To apply: https://weworkremotely.com/remote-jobs/mindrift-freelance-senior-python-developer-functional-test-frameworks