Application Software Engineer (Endpoint Security)

Application Software Engineer (Endpoint Security) at Oneleet (S22) $115K - $180K  •  0.01% - 0.05% YC's most popular security compliance platform (SOC 2, ISO 27001, HIPAA, GDPR) Remote (US) Full-time US citizen/visa only 6+ years About Oneleet Oneleet is a Y Combinator-funded cybersecurity startup that aims to make effective cybersecurity easy and painless for companies. The company provides a full-coverage cybersecurity platform through which companies can build, manage, and monitor their cybersecurity management program. The core product is a roadmap for companies that helps them become secure and build trust with their partners, which requires the implementation of numerous solutions like penetration testing, vulnerability assessments, awareness training, static code scanning, endpoint monitoring, and more. About the role Skills: Go, JavaScript, PowerShell, Bash/Shell Note: Even though the job posting only mentions US, we are looking for candidates from all NATO countries. Please only apply directly to this job posting. Messages sent outside of this platform will not be considered. About Oneleet Oneleet is a cybersecurity startup with a mission to revolutionize the industry. It aims to make effective cybersecurity easy and painless for companies by providing a comprehensive platform that helps companies build, manage, and monitor their cybersecurity program. We’re essentially building an all-in-one security platform that will allow companies to have everything they need under one roof to build a secure company. We have already built our own ASM (Attack-Surface Monitoring), CSPM (Cloud-Security Posture Management), MDM (Mobile-Device Management) and Vulnerability Management modules, and have many more on the roadmap. Oneleet is backed by top-tier venture capital firms including Y Combinator, and is part of their S22 cohort. The founding team has over 10 years of penetration testing and cybersecurity experience. Be a part of our team of opinionated rebels and help us create a category-defining company on a mission to reshape the broken and fragmented cybersecurity industry. Who we’re looking for At Oneleet we value individuals who are passionate and motivated to make a large impact in the cybersecurity ecosystem. We are looking for rebels with a growth mindset who love to take ownership, who exhibit excellent communication skills, and who have a "can-do" attitude towards technical challenges and innovation. A rebel’s mindset — we’re frustrated with the state of the cybersecurity industry, and believe that a rebel mindset is key to changing it. Opinionated (but not obstinate) — we believe that having an opinion is better than having no opinion, and helps us move more quickly. You’re excited about a role that requires hands-on coding, enabling you to address challenges and play a substantial role in shaping the trajectory of the Oneleet platform. Expert time management; we work with clients all over the world as well as have a team that is spread throughout multiple continents. We don’t expect anyone to be working or available 24/7- but we are looking for someone comfortable operating outside of the 9-5 mentality. Our core hours are 9am-1pm EST and expect that you can schedule your day effectively outside of that, while being flexible. Job Description: As an Engineer on the Oneleet Agent team, you'll be responsible for developing and maintaining our cross-platform endpoint security agent that monitors, configures, and protects employee devices. You'll work on everything from low-level system configuration automation to high-level API design that enables seamless communication between endpoints and our cloud platform. You'll architect solutions that collect security telemetry, enforce compliance policies, and monitor for vulnerabilities across Windows, macOS, and Linux environments. This role requires deep technical expertise in system programming, security best practices, and the ability to build software that operates reliably in diverse enterprise environments. As a seed stage startup, you'll collaborate directly with the founding team and have significant influence over the technical direction of our endpoint security capabilities. Key Responsibilities: Design and implement cross-platform agent functionality for Windows, macOS, and Linux using Go and JavaScript Build low-level configuration automation and system monitoring capabilities that interact with OS-specific APIs and security frameworks Develop secure communication protocols between agents and our cloud platform using gRPC or REST APIs Implement real-time threat detection and response capabilities at the endpoint level Create robust update and deployment mechanisms that ensure agents remain current without disrupting user workflows Build telemetry collection systems that provide visibility into device security posture while respecting privacy Collaborate with the security team to implement new detection rules and compliance checks Ensure agent performance is optimized to minimize system resource usage Develop comprehensive testing strategies for multi-OS compatibility Create tools and dashboards for monitoring agent health and deployment status across thousands of endpoints Qualifications: 5+ years of professional software development experience with a focus on systems programming or security software Strong experience with Go and JavaScript for building production-grade applications Deep understanding of operating system internals across Windows, macOS, and Linux Experience with low-level configuration automation and system administration across multiple platforms Proven experience with gRPC or REST API design and implementation Experience building software that runs with elevated privileges while maintaining security Strong understanding of endpoint security concepts and best practices Experience with cross-platform development challenges and solutions Excellent debugging and troubleshooting skills for complex system-level issues Bonus: Experience with Electron for building cross-platform desktop applications Bonus: Experience with Windows APIs, macOS system frameworks, or Linux kernel interfaces Bonus: Background in cybersecurity, particularly endpoint detection and response (EDR) or mobile device management (MDM) Bonus: Experience with certificate management and cryptographic operations Bonus: Familiarity with compliance frameworks (SOC2, ISO27001, HIPAA) Bonus: Experience with real-time data streaming and event processing Bonus: Bachelor's or Master's degree in Computer Science, Cybersecurity, or related field Why Oneleet: At Oneleet, you'll join a tight-knit crew of cybersecurity rebels on a mission to reshape the industry. We move fast, take ownership, and aren't afraid to disrupt stagnant business models to make security effortless for companies. Our "work hard, play hard" culture means we hold ourselves to high standards, then celebrate wins. Our leading-edge tech stack keeps things exciting for any geek. And our experienced team ensures you're always sharpening your skills. Bottom line, you'll have a blast doing deeply meaningful work. Expect hard problems, lots of autonomy, and plenty of growth. If you want your work to drive real change, this is the place to make your impact. Oh, and we offer all the usual startup perks too: Comprehensive benefits packages designed to support your health and well-being 🩺 Competitive comp & equity 💸 Plenty of PTO 🏝️ Floating holidays to honor the days that matter most to you 🎉 Flexible remote work 💻 Quarterly off sites to cool places (Amsterdam, Italy etc) ✈️ Technology We use Go and Prisma/Postgres on the backend and Typescript with React on the frontend. For task orchestration we use Temporal. Our applications are hosted on GCP using K8s.