Senior Identity & Access Engineer — SSO, MFA, RBAC

Scale AI, Inc.; Greater London; On-site; GBP 110,000 - 150,000; Full time

Job summary

Scale AI, Inc. in Greater London is seeking a senior engineer to design and build identity infrastructure focused on authentication and authorization across enterprise systems. You will implement SSO, MFA, and federated identity using SAML, OAuth, and OIDC, and apply ReBAC/RBAC and policy-based identity governance.

You will collaborate with product and security teams to drive secure, scalable solutions. Experience with distributed systems and public clouds (AWS) is essential, as is the ability

Qualifications

• 5+ years of engineering experience with infrastructure and identity systems.
• Hands‑on experience with OpenFGA, Authzed, Cedar, Topaz or similar authorization frameworks at scale.
• Strong understanding of Zanzibar‑based ReBAC models, relationship tuples, and access control evaluation.
• Strong knowledge of authentication standards such as OAuth 2.0, OIDC, SAML, and JWT, and IdP solutions like EntraID and Okta.
• Extensive experience with distributed systems and public cloud platforms (AWS preferred).
• Demonstrated track record of owning successful engineering projects and delivering outcomes.

Responsibilities

• Help design and develop core software systems for identity, access management, authorization, and authentication.
• Drive design and implementation of identity infrastructure for secure auth across enterprise systems.
• Build software for authentication mechanisms: SSO, MFA, and federated identity (SAML, OAuth, OpenID Connect).
• Build software for authorization mechanisms: ReBAC, ABAC, RBAC.
• Develop identity governance policies aligned with security standards and regulations (NIST, SOC2, ISO 27001).
• Present technical information to teams and stakeholders with guidance on identity management best practices.

Skills

5+ years engineering

Ownership

Communication skills

Independent delivery

Security and identity knowledge

Tools

OpenFGA

Authzed

Cedar

Topaz

OAuth 2.0

OIDC

SAML

JWT

EntraID

Okta

AWS

Zanzibar ReBAC

Job description

Scale AI, Inc. in Greater London is seeking a senior engineer to design and build identity infrastructure focused on authentication and authorization across enterprise systems. You will implement SSO, MFA, and federated identity using SAML, OAuth, and OIDC, and apply ReBAC/RBAC and policy-based identity governance.

You will collaborate with product and security teams to drive secure, scalable solutions. Experience with distributed systems and public clouds (AWS) is essential, as is the ability