Senior Software Engineer, Full-Stack - Security Platform

Vannevar is a defense technology company building AI to deter adversaries. They are seeking a Senior Software Engineer to join their Security Platform team, where the role involves building and scaling authentication and authorization systems that ensure secure access to sensitive data and workflows across national security and defense applications.

Responsibilities:

• Build and scale Vannevar’s centralized authentication and authorization platform, including tenant isolation across customer environments—from development through classified deployments
• Own the internal self-service platform for user, group, and permission management; partner with Design to deliver intuitive administrative experiences for developers and mission teams
• Build tooling and visualizations that help developers, administrators, and mission users understand and validate access permissions
• Own and evolve Vannevar’s platform management interfaces, including the feature flag system, to support new products and customer needs
• Partner with product engineering teams to build shared authorization and resource-sharing capabilities across the platform
• Shape the long-term roadmap for the Security Platform team by driving scalable platform capabilities and improving the developer experience

Requirements:

• 7+ years of software engineering experience, with a strong track record of designing, building, and operating scalable backend systems, and delivering full-stack features from conception through production
• Strong backend expertise, including proficiency in one or more modern backend languages (e.g., Python, Java), experience with relational databases (e.g., PostgreSQL), distributed systems, and API design
• Comfortable owning end-to-end development, including frontend work (e.g., React/TypeScript/Node.js) when needed, with a focus on delivering polished, customer-facing experiences rather than specializing exclusively in backend infrastructure
• Strong product intuition, with the ability to make pragmatic technical decisions, balance user needs with engineering tradeoffs, and thrive in ambiguous, fast-moving environments
• Experience with identity and authentication concepts and platforms, including OAuth 2.0, OpenID Connect (OIDC), SAML, JWTs, session management, RBAC/ABAC, SSO, Keycloak, OpenFGA, or other authentication and authorization systems
• Excellent cross-functional collaboration and communication skills, with experience partnering closely with product, design, security, and infrastructure teams, driving technical direction, and aligning stakeholders through ambiguity
• Active Security clearance or ability to obtain one and desire to travel to visit users, collect feedback, and debug issues
• Prior experience working in a user-facing product role