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

GitLab is the intelligent orchestration platform for DevSecOps. GitLab enables organizations to increase developer productivity, improve operational efficiency, reduce security and compliance risk, and accelerate digital transformation. More than 50 million registered users and more than 50% of the Fortune 100* trust GitLab to ship better, more secure software faster. The same principles built into our products are reflected in how our team works: we embrace AI as a core productivity multiplier, with all team members expected to incorporate AI into their daily workflows to drive efficiency, innovation, and impact. GitLab is where careers accelerate, innovation flourishes, and every voice is valued. Our high-performance culture is driven by our values and continuous knowledge exchange, enabling our team members to reach their full potential while collaborating with industry leaders to solve complex problems. Co-create the future with us as we build technology that transforms how the world develops software. *Fortune 500® is a registered trademark of Fortune Media IP Limited, used under license. Claim based on GitLab data. Fortune 100 refers to the top 20% ranked companies in the 2025 Fortune 500 list, published in June 2025. Fortune and Fortune Media IP Limited are not affiliated with, and do not endorse products or services of GitLab. 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 outcomes. - A product mindset and experience owning features end to end, including shaping scope, making trade-offs, engaging with users, and learning from adoption after launch. - A full stack background with a current focus on backend engineering, plus the ability to read modern frontend code and design effective APIs. - Strong application programming interface design and structured query language fundamentals. - Experience exploring artificial intelligence-assisted development. - The ability to work independently, collaborate across functions and regions, and support others through technical leadership and mentoring. Experience with GraphQL, PostgreSQL performance at scale, or building and evaluating large language model or agent systems is helpful but not required. We welcome candidates with different backgrounds and transferable experience. If you're excited about the role but don't meet every qualification, we encourage you to apply. About the team We are a team of four engineers, with two backend and two frontend engineers across Canada and Europe. You'll work in an all-remote, async-first environment with weekly sync calls, retrospectives, demos, and short iterations. This is early-