Senior Backend Engineer (Ruby), Plan: Spec-Driven Development

An overview of this role

As a Senior Backend Engineer on the Plan: Spec-Driven Development team, you'll help build GitLab's intent-to-code loop: agentic workflows that turn a stated intent into a refined work item, an implementation plan, and verified, mergeable code. You'll own early-stage backend work across the flows, application programming interfaces, data models, and evaluation systems behind this experience, using Ruby on Rails, Python, PostgreSQL, GitLab Duo Agent Platform, large language model application programming interfaces, and an artificial intelligence gateway.

You'll join a small, distributed team working on one of GitLab's highest-visibility product bets, collaborating with design partners toward a public beta. In your first year, you'll lead major features from an unclear problem through release, help shape scope with product and users, mentor other engineers, and influence technical decisions across agent workflows and evaluation methods.

What you'll do

• Lead backend features from early product discussions through technical design, implementation, rollout, and post-launch learning.
• Build the flows, application programming interfaces, and data models behind agent-generated work items, implementation plans, durable specifications, and mergeable code.
• Develop evaluation and benchmarking systems that measure workflow quality, token cost, and success rate.
• Use Ruby on Rails and Python to build reliable production systems, with PostgreSQL, GraphQL, representational state transfer, GitLab Duo Agent Platform, large language model application programming interfaces, and an artificial intelligence gateway.
• Collaborate directly with product, design, engineers, design partners, and users to shape scope and make practical trade-offs.
• Coordinate multi-person projects across the team and communicate decisions clearly in GitLab's asynchronous, all-remote environment.
• Mentor other engineers and contribute to technical direction across the Plan group and related artificial intelligence initiatives.
• Work in short iterations, share progress through demos, and use results and user feedback to guide what comes next.

What you'll bring

• Strong Ruby on Rails experience in a large production codebase and production experience with Python.
• Experience driving substantial projects with several engineers over multiple months, with clear user or business impact.