Node.js Runtime Protection Engineer at CloudLinux

Description

CloudLinux is a remote-first company dedicated to delivering high-volume, low-cost Linux infrastructure and security products. Our core principles emphasize doing the right thing, prioritizing employees, maintaining a remote-first culture, and enhancing operational efficiency for companies. We foster a supportive team environment where everyone contributes to collective success.

Imunify360 Security Suite, a flagship product of CloudLinux Inc., leads the market in security and stability for hosting providers. This innovative solution offers automated, user-friendly security specifically designed for shared, VPS, and dedicated servers. Its six-layer defense strategy ensures comprehensive attack prevention.

The Mission

Our mission is to protect web hosting providers and the websites on their infrastructure through a robust defense-in-depth stack. This includes a web server layer WAF, runtime application self protection for PHP, deep application integrations (like WordPress plugins), malware scanning with cleanup capabilities, and network layer firewalls with IP reputation. These components interoperate, and the extensive threat intelligence generated at scale powers advanced detection across the entire stack.

The Node.js segment of the hosting market is experiencing rapid growth, and we aim to build the next critical layer: runtime protection directly within the Node.js process. Most Node.js workloads on managed hosting today are AI-generated web applications deployed by non-technical owners who cannot, or should not, be expected to patch their own code or audit their dependencies. This role involves developing this runtime protection layer end to end, defending these applications without their cooperation and without causing disruptions.

What You'll Own

• The Product: As part of a brand new product line, you will define its scope, including what specific threats we intercept and the customer facing interface.
• The Technical Approach: You will determine the instrumentation strategy, deployment shape, and programming language. While consulting with our architects, the overall direction will be yours.
• Implementation, End to End: You will have access to a full suite of modern development tools, including LLM subscriptions and advanced infrastructure, to facilitate rapid development.
• Methodology: You will establish the methodology for building conviction in your detection logic.
• Cross-Layer Signal: Our existing stack provides unmatched threat intelligence from tens of millions of monitored sites, petabyte scale malware sample storage, and real time domain, URL, and IP reputation feeds, all available for you to integrate and leverage.

How We'll Measure Success

The product's success will be evaluated based on four key metrics: runtime overhead, false positives, false negatives, and customer escalation volume. Achieving excellent performance in these areas will ensure the product operates effectively across a significant portion of the modern Node.js web ecosystem.

What We're Looking For

We are seeking an experienced researcher or engineer capable of building and iterating on an entirely new product, driving both the research and development aspects. The primary challenge in this role is accurately distinguishing malicious or vulnerable patterns from legitimate but unusual code, consistently and correctly, across the diverse landscape of frameworks, libraries, and customer code encountered in production.

Requirements

Must have:

• Proven experience in building and shipping a new product, security solution, major feature, or technical system from scratch.
• Strong evidence of end to end technical ownership, encompassing initial investigation, architecture design, implementation, release, and production iteration.
• Deep web application security knowledge and current understanding of practical exploitation techniques.
• A functional understanding of how detection rules behave at scale, effectively catching attackers without inadvertently flagging legitimate code.
• Ability to independently fulfill the roles of Product Manager, Architect, Lead Engineer, and Quality Assurance for this product. You are proactive in seeking resources and assistance when needed.
• Comfort and proficiency in directing AI coding agents to produce high quality output.

Nice to have:

• Prior experience with runtime protection products, application firewalls, or instrumentation tooling.
• Background in malware analysis or incident response.
• Familiarity with managed hosting environments.
• Public security research, vulnerability disclosures, or authored detection rulesets.
• Familiarity with the Node.js runtime and the JavaScript ecosystem.

What it's not:

• This is not a scope and handoff role; you will drive the work and own the outcome.
• This is not a "platform team will productize this later" role; you will ship directly to real customer fleets and monitor telemetry closely.
• This is not a spec and review role; you will be hands-on every day.

Why this matters:

• Most managed hosting customers are not developers. They lack the ability to patch their applications or audit their dependencies. They will continue to deploy vulnerable code, often generated by AI assistants, as this is how modern web applications are increasingly built. Traditional advice like "secure your code, audit your dependencies" is not applicable to them.
• If we do not intercept exploits at runtime, these vulnerabilities will go unaddressed. Your success in achieving low detection, high performance, and minimal false positives will profoundly impact the stability and online presence of a significant portion of the modern web when new exploit classes emerge.

Benefits

• A strong focus on professional development.
• Engaging and challenging projects.
• Fully remote work with flexible working hours, enabling you to schedule your day and work from any location worldwide.
• Paid 24 days of vacation annually, 10 national holidays, and unlimited sick leaves.
• Compensation for private medical insurance.
• Reimbursement for co working spaces and gym/sports activities.
• A dedicated budget for education.
• The opportunity to receive a reward for innovative ideas that the company can patent.