Senior Backend Engineer, AI Engineering: Chat

GitLab; United Kingdom; Remote; GBP 110,000 - 160,000; Full time

Job summary

GitLab is seeking a Senior Backend Engineer for the Duo Chat team, focused on building core AI capabilities behind the GitLab Duo Chat interface. You’ll design flow components, integrate large language models, and orchestrate multi-agent flows that power AI features across the GitLab platform.

You will own backend features end-to-end, linking Python and Rails monoliths, with emphasis on reliability, performance, and secure AI integration at scale.

Qualifications

• Significant production Python backend experience with APIs and data models.
• Hands-on with AI-powered backend features and multi-agent orchestration.

Responsibilities

• Design and build flow components and agentic flows in Flow Registry using Python and LangGraph within Duo Workflow Service.
• Integrate new generative AI models, providers, tools, and multi-agent orchestration patterns into Duo Chat.
• Design, implement, and review GraphQL and REST APIs and monolith logic.
• Improve debugging, observability, and test coverage with pytest, RSpec, and related frameworks.
• Collaborate with Product, UX, frontend, and AI specialists to refine requirements.
• Document standards and patterns with engineers to enable safe AI integration.
• Participate in Tier 2 on-call rotations to troubleshoot production issues.

Skills

Python backend

AI-powered features

Ruby on Rails

REST/GraphQL APIs

SQL

performance & reliability

async workloads

LangGraph / LangChain

on-call rotations

Tools

LangGraph

LangChain

Job description

Remote, United Kingdom

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.

GitLab builds its product in the cloud, ensuring an accessible, scalable experience for contributors worldwide. The platform is designed to be user‑friendly, reliable, and secure, allowing developers to focus more on building code and less on managing infra. The GitLab crew prioritizes quality, transparency, and continuous improvement to keep pace with the industry’s rapid changes.

GitLab’s culture encourages globally distributed teams to work together efficiently, using AI and automation to streamline workflows and enable faster and safer delivery. Pioneering a unified DevSecOps approach, GitLab empowers teams to ship higher‑quality software at speed, providing a competitive advantage across the product development life‑cycle.

*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 Duo Chat team, focused on Chat Engine, you'll build the core AI capabilities behind GitLab Duo Chat, the natural‑language and agentic interface to the GitLab DevSecOps platform. Much of your work will involve building flow components and agentic flows in the Flow Registry, the Python framework built on LangGraph within our Duo Workflow Service that powers agentic chat, and integrating them with the GitLab Rails monolith.

You’ll own complex backend features from start to finish across both services. You’ll integrate large language models and orchestrate multi‑agent flows so customers can work faster and more securely across the software development lifecycle. This work sits where GitLab’s core platform meets its AI strategy, and reliability, performance, and answer quality directly shape the customer experience.

What you’ll do

• Design and build flow components and agentic flows in the Flow Registry using Python and LangGraph within the Duo Workflow Service. These reusable building blocks power agentic Duo Chat and, increasingly, other AI features across GitLab.
• Develop, ship, and maintain backend features for GitLab Duo Chat across the Python Duo Workflow Service and the GitLab Rails monolith in a secure, well‑tested, and performant way.
• Integrate new generative AI models, providers, tools, and multi‑agent orchestration patterns into Duo Chat to expand its capabilities and improve answer quality.
• Design, implement, and review GraphQL and REST application programming interfaces (APIs) and related monolith logic, including chat entry points, permissions, and foundational‑flow registration. Keep contracts with frontend clients and host systems reliable and clear.
• Improve debugging, observability, and test coverage using pytest, RSpec, and related frameworks; track and improve latency, error rates, and test coverage so AI‑powered chat workflows stay reliable at scale.
• Collaborate with Product, User Experience (UX), frontend, and AI specialists to refine requirements and deliver high‑quality improvements through iteration.
• Document standards, patterns, and learnings with other engineers, raising the bar for safe AI integration and evidence‑driven engineering.
• Participate in Tier 2 on‑call rotations to troubleshoot production issues, contribute to root cause analysis, and strengthen resiliency.

What you’ll bring

• Significant experience building and maintaining production Python backends, including APIs, data models, and asynchronous or long‑running workloads.
• Practical experience designing and shipping AI‑powered, agentic backend features, including large language model integration, tool or function calling, and multi‑agent orchestration. You use sound judgment about large language model limitations and safe use in production.
• Working proficiency in Ruby on Rails, or a strong willingness to learn it. Duo Chat integrates deeply with the GitLab monolith for chat entry points, GraphQL, permissions, and flow registration, and most of GitLab's codebase is written in Ruby.
• Proficiency designing or extending REST or GraphQL APIs with attention to scalability, maintainability, and backward compatibility.
• Strong Structured Query Language (SQL) skills and familiarity with relational databases such as PostgreSQL, including efficient queries and data modeling.
• Ability to find, diagnose, and prevent performance and reliability problems at scale.
• Experience solving technical problems of high scope and complexity and advocating for quality, security, and performance improvements across your team.
• Openness to learning and collaborating in an async‑first, distributed team, applying transferable skills from related technologies or domains. Hands‑on experience with agent frameworks such as LangGraph or LangChain is a strong plus.

About the team

We're part of GitLab's AI Engineering organization and own the AI‑powered chat experience embedded across the GitLab platform. Chat Engine is the backend‑focused team within the Duo Chat group.

We're backend, frontend, and AI specialists working asynchronously across time zones, using issues, merge requests, and documentation as our main collaboration tools. Our focus is to expand generative and agentic AI capabilities, improve the performance and reliability of chat workflows, and strengthen the debugging and testing foundations that let us run AI features safely at scale.

Please note that we welcome interest from candidates with varying levels of experience; many successful candidates do not meet every single requirement. Additionally, studies have shown that people from underrepresented groups are less likely to apply to a job unless they meet every single qualification. If you're excited about this role, please apply and allow our recruiters to assess your application.

Country Hiring Guidelines: GitLab hires new team members in countries around the world. All of our roles are remote, however some roles may carry specific location‑based eligibility requirements. Our Talent Acquisition team can help answer any questions about location after starting the recruiting process.

GitLab is proud to be an equal opportunity workplace and is an affirmative action employer. GitLab’s policies and practices relating to recruitment, employment, career development and advancement, promotion, and retirement are based solely on merit, regardless of race, color, religion, ancestry, sex (including pregnancy, lactation, sexual orientation, gender identity, or gender expression), national origin, age, citizenship, marital status, mental or physical disability, genetic information (including family medical history), discharge status from the military, protected veteran status (which includes disabled veterans, recently separated veterans, active duty wartime or campaign badge veterans, and Armed Forces service medal veterans), or any other basis protected by law. GitLab will not tolerate discrimination or harassment based on any of these characteristics. See also GitLab’s EEO Policy and EEO is the Law. If you have a disability or special need that requires accommodation, please let us know during the recruiting process.