Senior Software Engineer (Security)

Quick Facts

• Role: Senior Software Engineer (Security)

Description

Own and enhance the security-critical authentication stack that connects a phone to a device login experience. You will build Windows authentication components in Rust (credential provider, LSA authentication package, and CNG key storage provider), develop a cross-platform Bluetooth authentication daemon in Python, and implement enterprise identity flows and certificate/identity plumbing.

Responsibilities

• Build and maintain a Windows authentication stack in Rust (credential provider, LSA authentication package, CNG key storage provider)
• Extend Windows sign-in for Entra ID and Active Directory, including certificate-based logon, Kerberos, PKI, and certificate revocation
• Develop a desktop service: an asyncio Python daemon that brokers authentication between phones and computers over Bluetooth Low Energy
• Work on the Rust cryptography core shared with Python via PyO3 and the Flutter mobile app via flutter
• Ship backend identity features in FastAPI and Flask, including SAML, OIDC, and WS-Federation
• Evolve a protobuf protocol connecting mobile, desktop, and cloud components
• Harden solutions via threat modeling, mTLS, and security-minded code review
• Package, sign, and test releases for Windows, macOS, and Linux in CI

Requirements

• Strong systems programming skills in Rust and fluency in Python
• Real experience with Windows internals and authentication (Win32 APIs, credential providers, LSA, Kerberos, or smart card logon)
• Solid security background: applied cryptography, PKI, X.509, authentication protocols, and attacker methods
• Working knowledge of SAML, OIDC, and enterprise identity providers such as Entra ID and Active Directory
• Hands-on experience using AI agents (e.g., Claude) to write, review, and debug code, with good judgment about trust
• Generalist mindset: willing to learn unfamiliar parts rather than deferring work

Benefits

• 100% employer-covered health, dental, and vision
• Equity
• 401(k) match
• Flexible hours