Staff Software Engineer, Security Platform: Authentication

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 Staff Software Engineer on GitLab's Authentication team, you'll be the technical lead for how every user, application, token, and automated agent proves who it is on GitLab.com, Self-Managed, and Dedicated.

We're an OAuth 2.0 and OpenID Connect (OIDC) provider for millions of users. We also accept identity from enterprise identity providers through Security Assertion Markup Language (SAML) and Lightweight Directory Access Protocol (LDAP). Behind that sit more than ten token types and several session methods that grew inside the Ruby on Rails monolith. You'll help us move this work onto GATE, GitLab's new authentication and authorization platform. GATE exchanges external credentials for short-lived tokens at the edge through a Secure Token Service written in Go.You'll set our technical direction, lead the hardest protocol and migration work yourself, and help senior engineers own the rest.

Our projects include:

• OAuth across Cells: Making OAuth clients, grants, and tokens work when users and organizations live in different cells
• Global identities: One user identity that works across organizations and cells
• Token consolidation: Reducing the number of token types and moving token issuance and validation out of the monolith
• Identity for artificial intelligence (AI) agents and workloads: OAuth for Model Context Protocol (MCP) clients, workload identity federation, and service identities with narrow scopes

What you'll do

• Own the technical direction for authentication protocols at GitLab, including OAuth 2.0, OIDC, SAML, and token exchange, across the Rails monolith and GATE services.
• Write and drive design documents and architecture decision records (ADRs) for multi-quarter work, then break that work into increments that ship behind feature flags.
• Lead migrations that must not break existing customers: token formats, client and grant state, and session behavior on GitLab.com, Self-Managed, and Dedicated.
• Be hands-on in the most complex parts of the code, in Ruby on Rails and Go, and review the designs and merge requests of other engineers.
• Agree interface contracts with the GATE Core, GATE Infra, Authorization, and Tenant Scale (Cells and Organizations) teams, and keep them current as the architecture changes.
• Treat authentication as a security and availability boundary: threat-model new flows, add rate limits and abuse controls, and lead the technical response to authentication incidents.
• Mentor senior and intermediate engineers on the team and raise the protocol and security knowledge of the whole group.
• Work asynchronously with engineers in India, Europe, and the Americas, with most decisions made in writing.