Senior Backend Engineer (Ruby or Golang), Tenant Scale; Cells Infrastructure

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, Cells Infrastructure, you'll help us build the foundation that lets GitLab.com scale horizontally through our Cells architecture. You'll work on two core parts of that system: edge routing services that direct traffic across a fleet of independent Cell clusters, and the Topology Service that manages and serves cluster topology information as the source of truth for the rest of the platform. Your work will make routing reliable and low-latency across protocols, and ensure GitLab teams can build Cell-aware features with confidence as we grow.

Some examples of our projects

Building and operating routing services in TypeScript that direct requests to the correct Cell using cluster topology data

Developing and maintaining the systems that store, update, and serve cluster topology information that routing, resource assignment, and Cell lifecycle decisions depend on

What you'll do

Design and implement edge traffic routing that directs requests to the correct Cell in a way that's transparent to users.

Build and evolve the Topology Service that serves as the authoritative source of cluster state for routing, resource assignment, and Cell lifecycle decisions.

Collaborate across the GitLab Rails monolith and supporting services to make features and data models Cell-aware with feature teams across the product.

Operate and improve the routing and topology systems you build by participating in tier-2 on-call, responding to escalated incidents, and strengthening observability and operational tooling.

Author Architecture Decision Records (ADRs), operational runbooks, and documentation so other teams can understand, adopt, and extend the Cells platform.

Review merge requests from GitLab team members and community contributors, maintaining high standards for correctness, performance, and security across the stack.

What you'll bring

Experience building observable, resilient production services using Golang or Ruby on Rails (TypeScript experience is a plus).

Background delivering and operating production systems in high-scale environments, including incident response and operational ownership.

Ability to reason about distributed systems, including consistency models, partitioning strategies, failure modes, and operational tradeoffs.

Experience building high-throughput networking services (gRPC and protocol buffers knowledge is a plus).

Familiarity working in large, multi-team codebases and coordinating changes across teams and services, including making features and data models Cell-aware.

Knowledge of observability practices such as metric