GitLab
Senior
Build GATE, GitLab's new identity/access-management plane, while migrating auth off the Rails monolith
GitLab's Authentication team is building GATE, a centralized service for token issuance, validation, and identity that will underpin GitLab.com SaaS, Self-Managed, Dedicated, and air-gapped deployments. This Senior Backend Engineer role spans Ruby (Rails monolith) and Go (GATE), covering SSO/SAML/OIDC/SCIM/LDAP, passkeys, service accounts, and composite identities for AI agents.
Step into this interview
Free · a live voice mock calibrated to this exact role
What this interview tests
- Authentication/identity system design (OAuth, OIDC, SAML, SCIM, LDAP, JWT, RBAC)
- Token issuance, validation, cryptographic signing, and key management
- Migrating functionality out of a Rails monolith into a new service (GATE) across multiple deployment models
- Ruby and Go proficiency in a mission-critical SaaS context
- Security vulnerability triage (HackerOne-style reports) and access-management hardening
- Driving technical direction/roadmap and code-review standards as a senior IC
Common question themes
Design a token issuance and validation service that must work identically across multi-tenant SaaS, self-managed, and air-gapped deployments
How would you migrate an authentication code path out of a Rails monolith into a new Go service without breaking existing customers
Explain how you'd implement or evaluate passwordless/passkey authentication
Walk through triaging and remediating a reported authentication vulnerability
Describe a time you worked across two very different codebases/languages on the same feature
How do you decide what belongs in shared internal engineering standards vs. team-specific judgment calls
Related interviews
GitLab
Senior
Senior Solutions Architect, MEA
GitLab
Senior
Senior Solutions Architect - Northeast
GitLab
Senior
Engineering Manager, Data Foundations
Senior
Senior Software Engineer, Core Platform
Brex
Mid
Software Engineer II, Backend
Brex
Senior