Test Engineer, Endpoint

About Ent

Ent is the intent-aware workspace security platform for securing human and AI-driven work. Built to protect productivity, the new attack surface, Ent understands not just what users and agents do but why, and intervenes at the moment of risk before incidents occur. Where existing tools see events, Ent sees intent, so security teams can step in at the moment of risk instead of investigating days later. Founded by Lou Manousos and Brandon Dixon, co-founders of RiskIQ (acquired by Microsoft) and the team behind Microsoft Security Copilot, Ent is in production with Global 2000 customers across hospitality, financial services, and defense, and backed by Decibel, Sequoia, Crosspoint Capital, Craft Ventures, Shield Capital, Felicis, and In-Q-Tel. We’re now hiring the team that will define this category.

How We Work

Customer first. The product and the business are built around problems we’ve watched real security teams struggle with — not the other way around. Every roadmap conversation starts with what a CISO told us last week.

Humble. No drama. We hire people who share the mission and trust each other to deliver. Teamwork over showmanship. Accountability over politics. The work speaks louder than the person doing it.

Urgency. The window to build a durable security company in the AI era is open right now and it will not stay open. The shot clock has started. We move at the speed of the people we want to protect.

About the Role

Ent runs a single lightweight agent on machines we do not control. This role owns the evidence that the agent behaves correctly on real hardware across Windows, macOS, and Linux — the integration, performance, and reliability testing that stands behind every release decision.

What You’ll Achieve

• Own the integration and stress testing that verifies real agent behavior on production-representative machines across Windows, macOS, and Linux — asserting what the agent actually does at runtime, not just the values it reports.

• Architect and maintain the device test harness and the VM-based test farm behind it: image builds, provisioning, and parallel execution across the OS matrix, running nightly in CI.

• Design performance, load, and long-duration soak tests that surface resource-budget regressions before they reach a customer; define the utilization limits the agent must hold, and prove it holds them under load.

• Exercise the full agent lifecycle in test — install, enrollment, configuration delivery, staged self-update, rollback, and uninstall — across OS versions and upgrade and downgrade paths.

• Map coverage back to product intent: tie each detection to a test that fails when the behavior breaks, and close the gaps where a suite passes without ever exercising the behavior it claims to cover.

• Turn test results into a current, trustworthy report on release quality: coverage, failures, and outstanding risk.

• Drive high-severity, cross-layer defects to root cause at the OS-internals level, and turn recurring failures into durable regression coverage.

• Work directly with the endpoint engineers who own the code, giving them diagnostics and coverage they can act on.

What You’ll Bring

Required

• 6+ years in software test, SDET, or quality engineering, including substantial ownership of test infrastructure end to end — framework, CI, and reporting.=

• Built a device, integration, or cross-platform test harness from scratch and carried it through to a trusted, gating state.

• Depth in operating-system behavior on at least two of Windows, macOS, and Linux: process and resource accounting, install lifecycle, and agent- or driver-level runtime behavior.

• Strong Python (pytest), and able to read and wire C/C++ and Rust test suites into CI.

• Comfortable running large test fleets across virtualized environments, and working in CI systems — gating, parallelization, and artifact management.

• A track record of making CI trustworthy: reducing regression-suite runtime, or converting unreliable, non-gating suites into gates engineers actually rely on.

• Rigorous debugging — you reproduce, instrument, and prove root cause before proposing a fix.

• Treat test infrastructure as production software — reviewed, versioned, and maintained.

Preferred

• Hands-on with a virtualization and provisioning stack — Packer image builds with QEMU/KVM, VMware, or Parallels.

• CI experience with GitHub Actions, or a comparable system such as Jenkins or GitLab CI.

• Cloud familiarity — AWS, Azure, or GCP.

• Endpoint security experience — EDR, DLP, EPP, MDM, or systems-monitoring agents.

• Load and performance testing, and stress-harness design.

• Desktop GUI automation (PyAutoGUI, pywinauto, uiautomation or similar).

• Background in secure software development.

• Comfort incorporating AI-assisted tooling into a test workflow, including validating and refining its output.

Our Benefits

• Distributed workplace. While we have positions we hire for in our SF office, we also hire remotely across North America.

• Own a piece of the journey. Every teammate gets meaningful equity on top of their salary.

• We’ve got you covered. 90% of your medical, dental, and vision is paid by Ent. We also cover 75% for your dependents.

• Take the time you need. Our flexible PTO lets you recharge, travel, or just take a breather.

• Family matters. 12 weeks of fully paid maternity leave (birth, adoption, or foster) and 8 weeks fully paid paternity leave.

• Live well. A $100 monthly lifestyle account to spend on what keeps you healthy and happy — fitness, wellness, learning, and more.

• Set up your space. A $500 home office stipend when you join as a remote employee.

Diversity & Accommodations

We’re committed to building a diverse, inclusive, and equitable workplace where people of all backgrounds, identities, experiences, and abilities are welcomed, valued, and supported. We recognize there is no single path to success and value nontraditional career journeys and diverse perspectives as key to building stronger, more innovative teams.

We strive to ensure an inclusive experience at every stage of hiring and are happy to provide reasonable accommodations. If you require accommodations or accessible formats at any point during our process, please let your recruiter know. As an equal opportunity employer, our hiring process is designed to put you at ease and help you do your best work. If there’s anything we can do to improve your experience, we’re always open to feedback.