Sr Software Engineer, Applications

What You'll Do

• Extend our identity layer in Auth0: authentication flows, token issuance, identity federation.
• Build and maintain our ReBAC authorization model in OpenFGA, the system every authorization decision on the platform runs through.
• Own the details of OAuth 2.0 and OIDC in our stack: token flows, JWKS validation, scopes, audience restrictions.
• Define how AI agents authenticate and receive scoped permissions, so non-human actors operate under the same authorization model as people.
• Drive technical projects that cut across multiple teams and systems, from design through production.
• Set technical direction and quality standards for the team and review the work that ships against them.
• Support and mentor other engineers through code review, design discussions, and day-to-day collaboration.

What You Bring to the Table

• 5+ years of professional software engineering experience.
• Deep, hands-on knowledge of OAuth 2.0 and OpenID.
• Experience with ReBAC systems (OpenFGA, Zanzibar, SpiceDB): modeling schemas, writing and testing tuple-based policies, and reasoning about permission evaluation performance.
• Experience with Auth0 or a comparable identity provider (Okta, Azure AD, Keycloak).
• Strong backend skills in Java, Ruby, or Python, with frameworks such as Spring Boot, Rails, or Django.
• Regular use of AI coding tools (Claude Code, Cursor, Codex) for code generation, debugging, and exploring unfamiliar code, and the judgment to own and vet what they produce.
• A collaborative approach to design and decision-making, and a commitment to building an inclusive team.

Bonus Points

• Experience building or scaling auth systems for a platform with complex organizational hierarchies (agencies, multi-tenant SaaS, etc.).
• Familiarity with policy-as-code or attribute-based access control (ABAC).
• Background in ad tech or programmatic advertising.
• Contributions to open-source identity or authorization projects.

Our Tech Stack

• Languages: Ruby, JavaScript, Java
• Auth & Identity: Auth0, OpenFGA
• Infrastructure: AWS, Docker, Kubernetes
• Data: PostgreSQL, Redis
• Frameworks & Tools: Spring Boot, Rails, Node.js, React, RabbitMQ, Sidekiq

Integrity in Hiring

• At Basis, integrity is at the core of how we hire.
• To protect our candidates and our company, we verify identity, education, and employment history for all hires.
• Some roles may also require onsite or in-person interviews as part of the process.
• Any misrepresentation of identity, experience, or skills may result in removal from the hiring process or termination of employment.
• We value transparency and authenticity and expect the same from every applicant.

Anything Else?

• Don’t have every skill listed?
• No problem!
• We know experience can be built in many ways.
• If you have relevant skills that aren't reflected in your resume, we encourage you to share them in an optional cover letter.

Life With Basis

We’re committed to our people’s growth and well-being because our success is tied to theirs. That’s why we’ve earned recognition as a top workplace, including: Ad Age, #1 Best Places to Work, WorkLife's #1 Most Committed to Work Life Balance, and the Chicago Tribune's Top Workplaces in Chicago. We offer competitive perks, including a flexible work week, 401k/RRSP matching, mental health support, paid sabbaticals, generous parental leave, flexible work options, and more.

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