Senior Windows Developer

Job Description:

We are seeking a highly skilled Senior Windows Developer with expertise in authentication mechanisms, low-level Windows internals, and secure credential management. The ideal candidate will have extensive experience in developing authentication-based software and a deep understanding of Windows security architecture, authentication protocols, and driver-level programming.

Key Responsibilities:

• Develop and maintain authentication-based software, focusing on secure credential management and Windows authentication mechanisms.
• Design and implement Windows authentication components such as Local Authentication Subsystem (LSA), Credential Providers, and Security Support Provider Interface (SSPI).
• Work with Windows authentication protocols, including Kerberos, NTLM, OAuth, SAML, and Smart Card authentication.
• Develop and modify Windows Credential Providers to extend authentication functionality for login and enterprise security.
• Enhance and integrate authentication mechanisms with enterprise environments, including Active Directory (AD) and Azure AD.
• Utilize Windows API, LSA, and Win32 APIs to create robust authentication solutions.
• Develop and maintain Windows services, drivers, and system-level components to support authentication workflows.
• Perform security analysis and debugging of authentication mechanisms, working with debugging tools like WinDbg and Sysinternals Suite.
• Optimize authentication performance and security by implementing best practices in Windows security and cryptography.
• Ensure compatibility across various Windows versions and architectures, including 32-bit and 64-bit environments.
• Collaborate with security teams to ensure compliance with enterprise security standards and policies.

Essential Skills & Experience:

• Extensive experience in Windows system programming, including knowledge of Windows internals and authentication subsystems.
• Strong proficiency in C, C++, C#, and .NET for Windows application and system development.
• In-depth understanding of Windows authentication mechanisms, including:
• LSASS (Local Security Authority Subsystem Service)
• Credential Providers (V1 & V2)
• Security Support Provider Interface (SSPI)
• Windows Biometric Framework (WBF)
• Expertise in authentication protocols:
• Kerberos
• NTLM
• OAuth
• SAML
• LDAP
• RADIUS
• FIDO2/WebAuthn
• Experience with Windows system security tools, including debugging and forensic analysis using WinDbg, Process Monitor, and Event Tracing for Windows (ETW).
• Experience in developing and troubleshooting Windows services, DLLs, and drivers.
• Knowledge of Windows security policies, encryption, and certificate-based authentication (PKI, Smart Cards, TPM, BitLocker).
• Familiarity with Active Directory, Group Policy, and enterprise security best practices.
• Ability to analyze and reverse engineer security vulnerabilities in authentication workflows.

Preferred Qualifications:

• Experience with Windows Kernel Development and Windows Filtering Platform (WFP).
• Prior experience in developing Windows security products such as endpoint protection, identity management, or authentication solutions.
• Knowledge of PowerShell scripting and automation for security and system management.