Staff Engineer, Imunify360 Security Suite at CloudLinux

About CloudLinux

CloudLinux is a global remote-first company driven by the principles of doing the right thing, putting employees first, and maintaining a remote first culture. We specialize in delivering high-volume, low-cost Linux infrastructure and security products designed to enhance company operational efficiency. Our team culture emphasizes mutual support, ensuring every team member succeeds.

Learn more about us at cloudlinux.com.

The Role: Staff Engineer, Imunify360

We are currently looking for Staff Engineers to join various projects within our Imunify360 product. Imunify360 is CloudLinux's advanced, multi-layer security suite for Linux web servers, offering features such as antivirus and malware cleanup, Web Application Firewall (WAF), Intrusion Detection/Prevention Systems (IDS/IPS), Proactive Defense, patch management (KernelCare/Patchman), and IP/domain reputation monitoring. This suite operates across hundreds of thousands of shared, VPS, and dedicated hosting servers, supporting cPanel, Plesk, DirectAdmin, and standalone installations.

The engineering organization consists of over 60 engineers working in squads that cover backend, core services, server agents, malware research, WAF/WebShield, and Patchman. Core services are primarily built with Python, while agents and performance critical paths utilize Go and Rust. Our infrastructure runs on Hetzner and our own bare metal.

For more details on the product, please visit: https://imunify360.com/

Mission and Scope

The most intricate technical challenges within Imunify360 often transcend individual squad boundaries. A single change in detection logic can affect the scanner, agent, UI, reputation backend, and the overall release process. While squad leads manage delivery within their specific teams, the Staff Engineer acts as the technical alignment driver across the entire product. In this hands-on technical leadership role, you will tackle the most critical and high impact challenges as priorities shift, drive key technical decisions, enhance overall architecture, establish engineering standards, and assist teams in building sustainable solutions. This is an individual contributor position without direct people management duties. You will remain actively involved in development, dedicating approximately 30-50% of your time to writing production code rather than focusing solely on architectural design. While deep expertise in a specific domain is valued, this role demands the flexibility to engage across different components, collaborate with numerous squads, and address challenges where your unique expertise can make the greatest contribution.

What You Will Own

• Architecture and Technical Direction: Own the complete end to end architecture of Imunify360, encompassing agent to server to cloud backends, data flows, and the contracts between these systems. Drive and document Architectural Decision Records (ADRs) and Request For Comments (RFCs) for cross squad changes, coordinating with the Technical Director during weekly architecture syncs. Maintain a living technical debt and risk register (covering security, compliance, and uptime) complete with owners and deadlines, ensuring top items are prioritized on the roadmap.
• Tackling Cross Cutting Hard Problems: Focus on complex issues such as:
  • Agent resource footprint on densely shared hosts, including CPU, memory, and I/O budgets for scanning, file monitoring (inotify/fanotify), and WAF, measured on actual kernels rather than theoretical benchmarks.
  • Ensuring detection pipeline quality by managing false positive/false negative rates, and overseeing signature and ML model rollouts using staged gates and rollback capabilities.
  • Managing upgrade and release safety across a diverse fleet (CentOS, AlmaLinux, CloudLinux, Ubuntu, various control panels, and older kernels).
  • Addressing backend scalability and the cost management of reputation, ThreatIntel, and telemetry services.
  • Evaluating and executing migrations of performance critical paths from Python to Go/Rust when data supports the payoff, and knowing when to decline such migrations.
• Engineering Standards: Establish the benchmarks for design reviews, code reviews, testing strategy, observability (using tools like Prometheus, Grafana, and Sentry), and a secure Software Development Lifecycle (SDLC) adhering to OWASP ASVS and relevant CIS Benchmarks. Lead or co lead SEV1/SEV2 incidents when the root cause is unclear or spans multiple squads, ensuring blameless post mortems are issued within 24 hours and their action items are closed. Drive the practice of AI augmented SDLC by demonstrating effective agentic coding practices (prompt specificity, context provision, review quality, tool boundaries) in real changes.
• People Multiplier (No Direct Reports): Serve as a mentor to senior engineers and squad leads, guiding them toward staff level scope. Act as the technical advocate during hiring loops for senior and lead roles. Be the engineering representative in product and sales discussions, providing feasibility estimates and refusing commitments without prior written approval from a squad lead.

Key Milestones

• 30 Days: Successfully deploy at least one non trivial change to production. Be able to articulate the full request path from the agent to the backend. Maintain a personal list of the top 10 technical risks.
• 90 Days: Own a cross squad initiative that includes an approved ADR, a measured baseline, and a staged rollout plan. Have the risk register reviewed during architecture sync.
• 6 Months: The assigned initiative is live in production, complete with before and after metrics. At least one engineering standard (e.g., release gating, agent performance budget, design review template) is adopted by three or more squads.
• 12 Months: Be recognized by squad leads as the default escalation point for cross cutting technical decisions. Have mentored at least one senior engineer into a broader scope.

Requirements

Must Have

• 10+ years of experience building and operating production software, with at least 3 years operating at a Staff, Principal, or Tech Lead level spanning multiple teams.
• Strong production experience in Python and proficiency in at least one of Go or Rust.
• Deep understanding of Linux internals, including processes, filesystems, networking, kernel interfaces (like inotify/fanotify, eBPF or similar), packaging (RPM/DEB), and systemd.
• Proven track record in designing and operating distributed systems at massive scale, covering async backends, queues, databases, caching, and failure modes.
• Experience owning systems that run on customer machines (agents, daemons, on prem software) and understanding the implications of upgrade safety, backward compatibility, and resource budgeting.
• A strong security mindset, including threat modeling, secure coding practices, and handling untrusted input (such as files, HTTP traffic, or user content).
• Ability to write clear, concise technical documentation and drive decisions effectively in asynchronous, remote teams across various time zones.
• Daily use of AI coding tools (such as Cursor, Claude, MCP based tooling) and the ability to critically assess their output.

Nice to Have

• Experience in server security, including AV/malware detection, WAF (ModSecurity/Coraza), IDS/IPS, rootkit detection, and CVE/patch management.
• Experience with WordPress and Node.js web application hosting at scale.
• ML in production for classification or detection, including evaluation and safe model rollout.
• Experience with observability at scale, such as Prometheus, Grafana, Sentry, or ClickHouse.
• Ownership of CI/CD pipelines using GitLab CI, Jenkins, or build systems for multi-distro packaging.
• Contributions to open source projects in security or systems tooling.

Benefits

• Remain hands on technically while driving complex, high impact engineering work.
• Work on challenging problems in Linux, automation, and cybersecurity across both mature and evolving products.
• Influence technical direction and make impactful architectural decisions.
• Enjoy high levels of independence and ownership in your role.
• Fully remote work with flexible working hours.
• 24 paid vacation days, 10 national holidays, and unlimited sick leave.
• Private medical insurance compensation.
• Reimbursement for co working spaces and gym/sports memberships.
• Access to an education budget.
• Opportunity to receive a reward for innovative ideas that can be patented by the company.

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