Senior Software Engineer - Identity & Access Management

Brex•Seattle, WA

18h•Hybrid

About The Position

Brex is seeking a Senior Software Engineer to join the Identity and Access Management (IAM) team. This team is responsible for building and maintaining secure, user-friendly authentication and authorization systems. These systems protect users, safeguard company assets, and provide a seamless access experience for developers. The team owns critical platform capabilities including login methods, step-up authentication, custom authorization platform, account delegation flows, and core vendor integrations. As a Senior Software Engineer on IAM, you will lead projects to improve the security, reliability, and developer experience of these platforms. You will scope and drive projects, work cross-functionally, define technical quality, and help evolve the identity platform to support features like signed identity propagation, delegated and agent identity, fine-grained authorization, stronger auditability, and enterprise-ready customer authentication experiences.

Requirements

7+ years of professional experience designing, developing, and deploying applications.
Strong software engineering fundamentals and experience building reliable production backend systems.
Experience leading complex projects and mentoring other engineers.
Strong API design fundamentals, rigor around testing, code quality, and documentation.
An understanding of core IAM concepts such as authentication, authorization, sessions, tokens, MFA, SSO, OAuth, SAML, OIDC, or RBAC.
Clear communication, collaborates well across teams, and are effective in cross-functional technical discussions.
Demonstrating care about operational excellence and know how to improve system reliability, reduce toil, and maintain high-quality services over time.
Having a strong product and engineering judgment and can balance security, usability, and developer experience.

Nice To Haves

Experience working on identity and access management, authentication, authorization, or audit systems in a production environment.
Hands-on experience with Okta, Oso, SSO, SAML, OIDC, OAuth, passkeys, or WebAuthn.
Experience building enterprise-facing admin controls, custom roles, delegated access flows, or audit trails.
Worked on platform teams that provide shared infrastructure, paved roads, or secure-by-default frameworks for other engineering teams.

Responsibilities

Design, build, and operate backend systems and APIs for authentication, authorization, identity context, and audit-related workflows.
Lead engineers on initiatives end to end, from technical design and implementation through rollout, measurement, and operational support.
Improve login and access experiences across SSO, MFA, step-up authentication, delegated access, and enterprise identity flows.
Build and extend authorization systems that support custom roles, resource-aware access control, and secure defaults for product teams.
Help create durable, identity-aware audit trails and attribution for user, service, delegated, and agent-driven actions.
Partner closely with engineers across Brex to make IAM integrations secure by default and easier to adopt through clear patterns, tooling, and shared libraries.
Mentor engineers on the team to deliver high-quality code and produce operational improvements that raise the bar for reliability and maintainability across the team’s systems.