Senior Windows Internals Developer

About Transmit Security

Transmit Security is a recognized leader in identity and security, revolutionizing authentication and fraud prevention with cutting-edge technology. As we gear up for an exciting year, we are looking for exceptional engineers to tackle large-scale, complex challenges in security and authentication.

The FlexId Group is at the heart of our mission, responsible for building the infrastructure and features that power our core identity platform. This is an opportunity to work on high-impact, large-scale distributed systems that shape the future of identity security.

About the Role:

We are looking for an experienced Senior Software Engineer to drive the development of our high-performance client applications and the FlexID product ecosystem. This role is unique: while you will maintain and evolve our deep Windows C++ integrations, you will also take ownership of the broader FlexID server and web components that power our product across diverse environments.

Our solution is deployed both On-Premises and as a Cloud-Hosted managed service. This requires an engineer who can solve complex problems at the OS level while ensuring the entire product suite remains robust and scalable within virtualized and hosted infrastructures.

What You’ll Do:

• Develop and optimize Windows-based client applications using modern C++.
• Work closely with Windows OS components, including Windows Registry, COM API, Windows Events, and system services.
• Design and implement security-related features, integrating cryptographic protocols and authentication mechanisms.
• Debug, profile, and optimize performance to ensure reliability and efficiency.
• Collaborate with backend teams, security experts, and product managers to deliver secure, scalable solutions.
• Stay ahead of industry trends in security, Windows development, and authentication technologies.
• Cross-Stack Development: Maintain and optimize high-performance Windows client applications in modern C++ while contributing to the broader FlexID web and server ecosystem.
• System-to-Cloud Integration: Build and support features that bridge legacy Windows components (Registry, COM API, Services) with modern, platform-agnostic cloud services.
• Hybrid Deployment: Architect solutions that satisfy the unique constraints of both on-premises enterprise installs and scalable Cloud environments.
• Security & Identity: Design and implement cryptographic protocols and authentication mechanisms (e.g., RSA, SHA, Certificates, OIDC) across the entire product suite.
• Full-Lifecycle Ownership: Collaborate with backend and security teams to deliver end-to-end features, from low-level system hooks to high-level user interfaces.

What you’ll need:

• 5+ years of C++ experience: Deep expertise in building client-side applications with a strong command of Windows internals.
• Full-Stack Versatility: You are comfortable moving between system-level code and modern web/server stacks, leveraging AI and modern tools to solve problems regardless of the language.
• Architectural Breadth: Experience navigating the different security and networking requirements of On-Prem vs. Cloud deployments.
• Identity Foundations: Strong knowledge of security protocols and authentication standards (Kerberos, OAuth, etc.) is a plus.
• Results-Oriented: A problem-solving mindset focused on architectural integrity and product delivery rather than specific syntax.