Intermediate Backend Engineer, Authorization

An overview of this role

As a Software Engineer on GitLab's Authorization team, you'll help build and maintain the system that decides what every user, token, and automated agent can access on GitLab.com, Self-Managed, and Dedicated. You'll work alongside experienced engineers who guide the larger design decisions, delivering well-scoped changes and growing into ownership of larger parts of the system.

Today, that work is Ruby on Rails. Roughly 400 policy classes and a catalog of about 1,900 permissions sit behind every application programming interface (API) request. You'll work on fine-grained token permissions, custom roles, and the GraphQL and representational state transfer (REST) APIs that enforce them. A single request can trigger hundreds of permission checks, so correctness and performance both matter.

You'll also contribute to moving the permission model to a new authorization stack that pairs the Rails monolith with a Rust policy engine. The engine represents access relationships and evaluates permission rules, and can run within the monolith's process or be reached through remote procedure calls using gRPC. You don't need prior Rust experience: several engineers on the team learned it for this work, and we'll support you doing the same.

Some examples of our projects:

• Refactoring GitLab's policy layer so the same permission definitions can be evaluated by the monolith and the new authorization service
• Extending fine-grained token permissions to more resources, with guidance from senior engineers on the design

What you'll do

• Implement authorization changes in GitLab's Ruby on Rails monolith so permission checks allow intended access and deny unauthorized access.
• Deliver well-scoped workstreams from feature-flagged rollout through verifying that the old and new systems produce the same results, with review and guidance from senior engineers.
• Build and extend fine-grained permissions for tokens and roles so additional resources have permission coverage consistent with the established catalog.
• Extend and fix authorization enforcement so GraphQL and the REST API enforce the intended permissions consistently.
• Make incremental refactors to long-lived policy code without changing behavior for existing customers.
• Investigate and fix reliability, performance, and secu