Principal Support Engineer, Endpoint

Be an Early Applicant Remote Hiring Remotely in USA Senior level Remote Hiring Remotely in USA Senior level Serves as the endpoint security subject-matter expert for support, Sales Engineering, and Customer Success. Diagnoses complex Windows and macOS endpoint issues, analyzes telemetry and logs, troubleshoots integrations with EDR, DLP, and MDM products, and provides prioritized customer recommendations. Partners with Engineering and QA on defect investigation and validation, maintains lab capabilities, and creates runbooks and documentation. The role also enables field teams to explain endpoint findings and improve customer outcomes. The summary above was generated by AI Principal Support Engineer - EndpointDOMAIN SUBJECT-MATTER EXPERT · ESCALATION & ENABLEMENT

About the role

Reach Security tells organizations what their existing security tools should be doing with the products they already own - and proves it. As a Principal Support Engineer, Endpoint, you are Reach’s senior domain authority on everything endpoint.

This is not an endpoint break/fix role. You won’t spend your days administering endpoints, packaging agents, or chasing agent crashes. You’ve already done that work - for years - and that is exactly what qualifies you. Those years in the trenches are what let you look at a customer’s endpoint configuration, their controls, and Reach’s findings and say, with authority, what matters, what doesn’t, and why.

In this role you put that hard-won judgment to work advising the field, guiding customers through their hardest problems, sharpening Reach’s recommendations, and troubleshooting how Reach integrates with the endpoint products already in a customer’s environment. It is a high-agency individual-contributor role for a proven expert who is energized by unfamiliar problems rather than thrown by them.

What this role really does

You’ll serve three audiences at once, and the strongest people in this seat move fluidly between them:

• Enable the field (Sales Engineering & POVs). Help SEs build the strongest possible POV from Reach’s endpoint findings - translating raw product output into “here’s the risk, here’s why it’s urgent, here’s what to fix first.” Coach the technical field team to defend those findings under technical scrutiny and tell Engineering and Research what would make the next POV even more compelling.

• Empower Customer Success. Be the deep technical resolver behind CS. When a customer hits a genuinely hard endpoint-related problem, you investigate to root cause, propose the solution, and hand Engineering a clean, reproducible diagnosis - so engineers validate and ship rather than doing front-line discovery.

• Harden the product. Own your share of the escalation queue and close the loop: solve, reproduce, test, document, and enable - so each issue makes Reach more robust and each runbook makes the whole team faster.

How you’ll spend your time

• Serve as the endpoint subject-matter expert for the support team - review customer endpoint configurations, controls, and policies and make sage, prioritized recommendations grounded in real-world best practice.

• Critique Reach’s endpoint findings, so customers are presented only with what truly matters - separating signal from noise and articulating why a finding is urgent, or why it isn’t.

• Troubleshoot integrations between Reach and third-party endpoint and security products (EDR, DLP, MDM, and similar) - using your deep knowledge of how those products actually behave to pinpoint where an integration breaks and propose the fix. This is where your hands-on background is exercised most directly.

• Diagnose deep, engineering-level customer issues end to end - using logs, telemetry, diagnostics, and OS-level reasoning to reach true root cause, then packaging a clear diagnosis and proposed fix that Engineering can act on quickly.

• Uplevel the Sales Engineering team - teach the field to read and explain endpoint findings, defend recommendations to customer security teams, and translate product output into what matters to the customer.

• Partner with Engineering and QA to report defects, validate fixes, confirm workarounds, and drive root-cause analysis.

• Author and maintain runbooks, troubleshooting guides, and internal documentation that turn your field experience into repeatable team knowledge.

• Maintain enough of a lab or test capability to validate hypotheses about endpoint behavior and integration edge cases.

The experience below is the foundation we’re hiring for. You’ve done this work hands-on, at depth, earlier in your career - and in this role you’ll leverage that judgment as a subject-matter expert rather than performing it day to day. We’re screening for the expertise that experience produced, not for a desire to keep doing endpoint administration.

• 6+ years of deep, hands-on experience with Windows and macOS endpoint agents and endpoint security in enterprise environments - enough to have developed genuine expertise, not passing familiarity.

• Time in a senior individual-contributor role such as L3 Support Engineer, Endpoint Engineer, Windows/macOS Engineer, or Security Support Engineer.

• Demonstrated command of endpoint agent behavior across Windows and macOS - installation, upgrades, persistence, OS compatibility, performance, and stability - and the judgment to know what “good” looks like.

• Kernel-level understanding of Windows, including ETW, WFP, memory management, process/thread behavior, and driver interactions.

• macOS internals experience, including the Endpoint Security framework, System Extensions, FSEvents, MDM interactions, notarization, code signing, and process lifecycle.

• A track record of analyzing endpoint telemetry, logs, and diagnostics to reach root cause in complex system interactions.

• Experience resolving interoperability issues between endpoint agents and security tools (EDR, DLP, MDM, or similar).

• Working knowledge of Linux system administration, sufficient to reason about supporting services that interact with endpoint deployments.

• Experience with enterprise-scale environments and large endpoint fleets.

• The advisory instinct that defines this role: the ability to look at a set of findings and controls and tell a customer, clearly, which few things matter and why.

• Strong written and verbal communication - you can make a complex endpoint issue clear to a customer, an SE, and an engineer, each in their own language.

• Strong time management and a real sense of urgency in customer-impacting situations.

• BS or MS in Computer Science, Engineering, or a related technical discipline - or equivalent practical experience.

Cross-domain fluency we value

Reach spans the whole security stack, and the best domain experts are curious well past their specialty. You don’t need to be an expert in all of these, but comfort in several will make you far stronger here: identity and IDP troubleshooting (SSO, SAML/OIDC, layered and conditional access, MDM-to-IdP interactions); a working grasp of threats and vulnerabilities and how they manifest at the endpoint; and familiarity with email security controls. We’ll gladly help you deepen the areas you’re newer to.

Nice to have

• Experience supporting endpoint security, insider risk, or behavioral-analytics platforms.

• Experience reproducing customer issues in labs that mirror production endpoint configurations.

• Exposure to cloud or hybrid enterprise environments (AWS, Azure, GCP).

• Linux internals: kernel/user-space boundaries, eBPF, LSM (SELinux/AppArmor), cgroups and namespaces, netfilter, systemd, proc/sysfs, inotify/fanotify, auditd/seccomp, ELF/ptrace.

• Hands-on experience with third-party endpoint security products such as CrowdStrike Falcon, Microsoft Defender, SentinelOne, or similar.

Who you’ll thrive as

You’re the person peers escalate to - and still the first to say “I haven’t seen that before, let me dig in.” You think in systems, you’re relentless about root cause, and you’re generous with what you learn. You’re as comfortable teaching the field how to defend a finding as you are reading a kernel trace. Curiosity, adaptability, and low ego matter to us as much as depth: the security stack keeps changing, and we’re looking for someone who’s genuinely excited by that.

Working at Reach Security:

• Competitive salary, and equity package

• Comprehensive benefits package including:

• Medical, dental, and vision insurance, including plan options with company-paid employee coverage

• FSA, HSA, and 401(k) plans

• Company paid life insurance and disability coverage, along with buy up options

• Voluntary benefits including pet insurance, identify theft coverage, and legal services

• Unlimited PTO and sick time