Senior Backend Engineer

About the Role:

As a Software Engineering Expert, you'll create the training data that teaches AI models to think like real software engineers. Working with production-scale codebases across multiple languages and frameworks, you'll design complex, multi-file engineering tasks that reflect the messy reality of professional software development. In this role, you’ll function as an AI Engineer — building the evaluations and datasets that define frontier model capabilities and shape the future of AI-assisted software development. You’ll be responsible for designing and validating authentic software engineering challenges, contributing to both open-source and private repositories, and collaborating with expert engineers to create realistic, production-grade code, problem statements, and test suites that mirror real-world complexity.

Responsibilities:

• Design and develop realistic software engineering tasks in production-scale environments across various domains — backend, frontend, and infrastructure.
• Create novel contributions to open-source repositories, including new features, refactors, and genuine bug fixes.
• Draft detailed and comprehensive problem statements that mirror real-world product and technical requirements.
• Build reference implementations showcasing optimal solutions, with strong attention to edge cases and system-level trade-offs.
• Develop and maintain robust test suites to validate functionality across multiple components and ensure integration within larger systems.
• Document reasoning traces that reflect the systematic problem-solving approach of experienced engineers.
• Review and provide detailed feedback on code and task submissions from other contributors to uphold high-quality standards.
• Collaborate cross-functionally to enhance data creation infrastructure and improve overall engineering practices.

Qualifications:

• 4 plus years of professional software engineering experience in production codebases, with a proven track record of shipping features and solving complex technical problems.
• Strong programming fundamentals and proficiency in a backend language (e.g., Python, Java) and frameworks such as Django, Flask, or Spring.
• Solid understanding of backend systems and how databases, APIs, and services integrate within an application.
• Ability to work with ambiguity and navigate unfamiliar, legacy, or imperfect codebases effectively.
• High attention to detail — capable of anticipating edge cases and maintaining comprehensive test coverage.
• Self-driven and reliable, with excellent time management and ability to deliver high-quality results independently.
• Exceptional written communication skills, including the ability to document reasoning and provide clear technical feedback.
• Hands-on experience with multiple programming paradigms and frameworks (e.g., React, Next.js, Django, Spring, distributed systems).
• Demonstrated contributions to open-source projects or experience in reviewing pull requests.
• Experience working in large, complex, or legacy codebases with intricate dependencies.