Senior Software Engineer

Senior Software Engineer Endpoint Sensor

About Mimecast

The work people build is worth protecting and its harder to protect than it used to be. AI agents now move at machine speed with human-level access and a small slip-up can become a very public one. We disrupt cybercriminal activity before that happens. We think fast go big and always demand more of ourselves. We work hard deliver and repeat. We grow with real determination and put success well within reach. We push each other to be better and expect to be pushed back in a community built on respect where everyone is counted. Work Protected.

Overview

Incydr Product Development is looking for a Senior Software Engineer to join the Endpoint Data Protection team. Reporting to the Senior Manager - Engineering youll help protect organizations from data loss and insider risk across millions of endpoints as we invest in the next generation of that protection: defending data wherever it moves however it moves.

This is a foundational role working on our endpoint sensor technology that runs continuously and reliably on millions of corporate machines across Windows macOS and Linux. Youll work at the lowest levels of the operating system building kernel drivers and Endpoint Security extensions that power how Incydr detects and stops data loss and insider risk. Youll own features end to end from early research and proof of concept through production at scale.

Mimecast is an AI-First engineering organization. Our teams actively leverage AI-powered development tools across all facets of engineering and were looking for someone genuinely curious about working this wayincluding bringing that curiosity to securing the AI-driven workflows this role increasingly has to defend against.

What Youll Do:

• Design and develop core capabilities for our Windows macOS and Linux agents throughout the complete software development and release lifecycle.

• Work at the OS boundary building performant reliable kernel-mode components and Endpoint Security and Network extensions that handle complex system interactions.

• Build detection paths and real-time inline enforcement moving beyond telemetry and alerting to deny/block decisions without compromising endpoint performance.

• Own features end to end from early research and proof of concept through production at scale and integrate agent capabilities with backend and product workflows.

• Build always-on components with strong observability performance and stability in production.

• Bring an adversarial security-first mindset to everything you build designing components that resist evasion and treat all input as untrusted.

• Collaborate with product and cloud service teams to turn discoveries into capabilities that support real-world security investigations.

What Youll Bring:

• Deep experience building production software including substantial work in low-level systems or endpoint development and code that runs continuously and reliably across large-scale endpoint or systems deployments.

• Low-level endpoint development expertise on at least one platform: Windows kernel mode including minifilters drivers WFP and C; or macOS Endpoint Security and Network Extension frameworks using Swift or C.

• Strong C fundamentals with sound judgment about memory concurrency and performance trade-offs and fluency with the debugging and profiling tools this work demands.

• Experience designing extensible software architectures including library boundaries and interface contracts with the discipline to maintain and evolve long-lived code.

• A security mindset that accounts for both evasion and adversarial behavior and how authorized users move data. This is insider risk not just external attackers.

• Experience building real-time inline enforcement and deny/block pathsnot just detection and telemetryunder the strict performance and stability constraints of always-on endpoint software.

• Performance discipline: you build always-on software that earns its place on the endpoint and never degrades the users experience applying profiling caching and memory-management techniques.

• Comfort working daily with AI coding assistants and agents with an interest in helping secure the AI-driven workflows customers are adopting.

• Cross-platform development experience across Windows macOS and Linux.

• Network-layer monitoring experience including user-space traffic capture TLS-aware analysis macOS Network Extensions or the Windows Filtering Platform.

• Exposure to data security DLP or content-classification conceptsor genuine eagerness to grow into the data-centric problem space including file-activity telemetry content hints and egress enrichment.

• Experience shipping enterprise endpoint software including silent installation automatic updates multi-tenant configuration and the operational reality of heterogeneous corporate fleets.

• Production experience with Rust or demonstrated ability and interest in working in a Rust codebase.

• A background in behavioral analytics or adjacent detection domains.

The base salary range for this position is $148000-$222000 plus benefits. This range represents the minimum and maximum new hire compensation for this role. The position may also be eligible for incentive plans and additional benefits in accordance with company policy and local regulations. Our salary ranges are determined by role level and location with individual compensation also dependent on factors such as qualifications experience and skills. Final offers will reflect these considerations and may vary accordingly.

Belonging at Mimecast

Cybersecurity is a community effort. Thats why were committed to building an inclusive diverse community that celebrates and welcomes everyone unless theyre a cybercriminal of course.

Were proud to be an Equal Opportunity and Affirmative Action Employer and wed encourage you to join us whatever your background. We particularly welcome applicants from traditionally underrepresented groups.

We consider everyone equally: your race age religion sexual orientation gender identity ability marital status nationality or any other protected characteristic wont affect your application.

If you require any adjustments or accommodations due to a disability or any other reason that may help you in your interview process please let us know by emailing

Due to certain obligations to our customers an offer of employment will be subject to your successful completion of applicable background checks conducted in accordance with local law.

It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment.