Backend Engineer (Ruby), AI Engineering: Agent Foundations

Job summary

Responsibilities

As an Intermediate Backend Engineer in GitLab's Agent Foundations stage, you'll go beyond using AI tools. You'll help build the foundations for GitLab's agentic AI experiences: the platform that lets AI agents work across the whole software delivery lifecycle, not just write code.

• Develop, ship and maintain features for the Duo Agent Platform in the GitLab monolith (Ruby) and, where needed, the AI Gateway (Python).
• Work with Product Management, UX, frontend, backend and AI specialists to refine requirements and ship improvements in small iterations.
• Design, implement and review GraphQL and REST APIs and the backend logic behind them, with reliable, scalable and clear contracts for clients.
• Improve and extend automated testing (RSpec and other frameworks) to strengthen quality and give developers faster feedback.
• Share standards, patterns and learnings with other engineers to raise the bar for responsible AI integration and evidence-driven engineering.

What they're looking for

• Experience building and maintaining production Ruby on Rails applications, including background jobs, APIs and data models.
• Comfort working across the stack in a mature codebase. Familiarity with Python backends and/or Vue frontends is a plus.
• Skill in designing or extending REST and/or GraphQL APIs with attention to scalability, maintainability and backward compatibility.
• Real enthusiasm for AI and hands-on experience using AI tools in your daily work. Experience designing and shipping AI-powered backend features or integrations is a plus.
• Proven SQL and experience with relational databases such as PostgreSQL, including writing efficient queries and data modeling.

Tech stack

• Python
• SQL
• PostgreSQL