Senior Software Engineer (Remote | $30–$100/hr)

Synthires; Greater London; On-site; GBP 31,000 - 104,000; Full time

Job summary

Synthires in the United Kingdom is seeking experts to create realistic coding tasks and deterministic verifiers that distinguish valid solutions from incorrect ones.

You will debug, test, and refactor code, evaluate solutions with rigorous reviews, and start within 24–48 hours of onboarding.

Approximately 100 positions available with output-based compensation and flexible engagement.

Qualifications

• Strong backend experience with Java, Node.js, Go, Rust, TypeScript, Python, C++.
• Experience building scalable services and APIs.
• Strong debugging, performance optimization, and automated testing skills.
• Solid code review and software engineering judgment.

Responsibilities

• Create realistic coding tasks involving feature implementation and bug fixing.
• Build deterministic verifiers that accept valid solutions and reject incorrect ones.
• Debug, test, optimize, and refactor code.
• Evaluate solutions using strong code review and testing practices.

Skills

Backend languages

APIs & services

Code review

Testing skills

Debugging & performance

Job description

Help train next-generation AI systems by creating challenging coding tasks and implementing deterministic verifiers that distinguish valid solutions from incorrect ones. No prior AI experience is required — your software engineering expertise is what matters.

Key Responsibilities

• Create realistic coding tasks involving feature implementation and bug fixing.
• Build deterministic verifiers that accept valid solutions and reject incorrect ones.
• Debug, test, optimize, and refactor code.
• Evaluate solutions using strong code review and testing practices.

Required Qualifications

• Strong backend experience with Java, Node.js, Go, Rust, TypeScript, Python, C++, or similar.
• Experience building scalable services and APIs.
• Strong debugging, performance optimization, and automated testing skills.
• Solid code review and software engineering judgment.

Preferred Qualifications

• Experience with large-scale application development and refactoring.
• Strong knowledge of algorithms, data structures, and computer science fundamentals.
• Experience designing test strategies, maintaining large test suites, or diagnosing flaky tests.
• Strong analytical, problem-solving, and technical communication skills.

Compensation

• $30–$100/hour, output-based.
• Approximately 100 positions available.
• Minimum weekly task submissions apply.

Start Timeline:

• Selected experts are expected to begin their first tasks within 24–48 hours of onboarding.