Remote Senior Backend Engineer - Ruby & AI-Driven Workflows

JobCubby; Poland; Remote; PLN 272,000 - 408,000; Full time

Benefits offered by this job

Flexible PTO

Equity program

Development fund

Parental leave

Job summary

GitLab is seeking a Senior Backend Engineer for the Plan: Spec-Driven Development team, shaping agent-driven workflows and backend systems with Rails/Python. You will own early-stage backend work across flows, APIs, and data models, collaborating with design partners to deliver high-visibility features in a remote, async-first setting.

In your first year, you will lead major features from unclear problems through release, mentor others, and influence decisions across agent workflows and

Qualifications

• Strong Rails experience in a large production codebase.
• Experience leading substantial projects with several engineers over multiple months.
• Product mindset with end-to-end ownership, shaping scope and engaging with users.
• Ability to read modern frontend code and design effective APIs.

Responsibilities

• Lead backend features from early product discussions through design, rollout, and post-launch learning.
• Build the flows, APIs, and data models behind agent-generated work items and durable specs.
• Develop evaluation systems to measure workflow quality and cost.
• Use Rails and Python to build reliable production systems (PostgreSQL, GraphQL, AI gateway).
• Collaborate with product, design, engineers, and users to scope and trade off decisions.
• Coordinate multi-person projects and communicate in an asynchronous, all-remote environment.
• Mentor engineers and influence technical direction across AI initiatives.
• Work in short iterations, demo progress, and use feedback to guide next steps.

Skills

Ruby on Rails

Python

API design

Full stack

Mentoring

Tools

GraphQL

PostgreSQL

Duo Agent Platform

Job description

GitLab is seeking a Senior Backend Engineer for the Plan: Spec-Driven Development team, shaping agent-driven workflows and backend systems with Rails/Python. You will own early-stage backend work across flows, APIs, and data models, collaborating with design partners to deliver high-visibility features in a remote, async-first setting.

In your first year, you will lead major features from unclear problems through release, mentor others, and influence decisions across agent workflows and