--- title: 'Backend engineer at protocolnine.com' canonical: 'https://feeny.ai/job/backend-engineer-protocolnine-com-san-jose-r3zhzvjt1f9j' type: 'job' last_seen: '2026-10-18' --- # Backend engineer at protocolnine.com - **Company:** protocolnine.com - **Location:** San Jose, CA - **Compensation:** $150k–$200k - **Employment:** full-time - **Work type:** remote - **Posted:** 2026-04-28 - **Last confirmed live:** 2026-10-18 - **Apply:** https://jobs.gem.com/protocolnine-com/am9icG9zdDr6RilFZPkwr9pczfyFGKij ## Job description ## Role Summary We’re building a new category of enterprise security infrastructure for modern, AI-driven systems. As a backend engineer, you’ll work on the core systems that power policy management, threat evaluation, observability, and integrations with external systems—enabling enterprises to evaluate threats, enforce policies, and gain visibility into agentic and API-driven workloads. You’ll also play a key role in shaping how AI and agentic systems are built, orchestrated, and secured in production, working on real-world applications of LLMs and autonomous workflows. This is a hands-on role for someone who enjoys building from first principles and shipping systems that operate reliably at scale. ## What you’ll do - Design and build systems for policy definition, enforcement, and real-time decision workflows, incorporating AI and agentic technologies - Build and evolve systems that support agent orchestration, reasoning workflows, and secure execution patterns - Develop a robust integration layer connecting with cloud platforms, APIs, and third-party systems - Build infrastructure for telemetry, logging, and auditability, including visibility into agent behavior and decisions - Design extensible APIs and data models across relational, NoSQL, and graph-based systems to power intelligent systems - Own problems end-to-end—from shaping requirements to production rollout and iteration - Work closely with product and engineering to define what should be built, not just how ## What we’re looking for - 4+ years of experience building backend or distributed systems - Strong in one or more: Python, Go, Java, or TypeScript - Experience building and operating systems in production environments - Experience working with APIs and integrations (REST, event-driven, or streaming systems) - Comfortable navigating ambiguity and making forward progress without perfect information Bonus: - Former experience as early engineer at a startup - Experience in security, infrastructure, or networking - Experience integrating with cloud providers or external SaaS systems - Familiarity with observability systems, knowledge graphs, or complex data modeling - Hands-on experience or strong interest in LLMs, agentic systems, or AI-powered workflows What makes someone successful here - You take ownership of problems and drive them to completion - You think in systems and workflows, including how they interact with external environments - You care deeply about reliability, debuggability, and performance - You design for extensibility and integration from day one - You’re curious about how AI systems behave in production and how to make them safe and reliable - You’re energized by building in areas without established playbooks ## Why this role - You’ll help define how enterprises secure agentic and autonomous systems - You’ll solve problems at the intersection of systems, security, and AI - You’ll have real ownership and influence over the direction of the product - You’ll build systems from the ground up in a fast-moving environment ## About protocolnine.com ## Company Overview - **One-liner**: Protocol Nine is a stealth-mode cybersecurity startup building an AI-native security platform that leverages specialized small language models and agentic systems for real-time threat detection and automated policy enforcement. - **Entity Type**: Private (Seed Stage – raised $8.8M of a $9.99M offering as of March 2026) - **Headquarters**: Saratoga, California, United States - **Founded**: 2025 - **Founders**: Sanjay Kalra and Murat Bog (named as executives in SEC filings) ## Core Business - **Primary industry/industries**: Cybersecurity, Artificial Intelligence, Network Security Infrastructure - **Target customers**: Enterprise organizations needing next-generation network security and automated threat response - **Mission or purpose statement**: To redefine network security by building an AI-native platform that provides real-time threat detection and automated policy enforcement, protecting critical assets in evolving digital environments. ## Products & Services - **AI-Native Security Platform**: A next-generation security infrastructure platform that uses specialized small language models and agentic systems for real-time threat detection, automated policy enforcement, and adversarial robustness. The platform is designed for edge deployment and integrates into security pipelines. ## Market Standing - **Valuation/Market Cap**: Not disclosed (private company) - **Key Metric**: **Total Funding** – $8,799,989 raised from a $9,999,987 Series Seed offering (as of April 2026), with 9 investors. - **Notable Investors/Partners**: Details of the 9 investors are not publicly named in the SEC filing. The company is backed by undisclosed institutional or accredited investors. - **Growth Signals**: The company successfully closed a seed round of ~$8.8M in its first year of operation (founded 2025, funding in early 2026). It is actively hiring for key technical roles (Backend Engineer, AI Lead), indicating rapid team expansion and product development. ## Competitive Advantages - **AI-Native Approach**: Unlike traditional security vendors that bolt on AI, Protocol Nine is building its platform from the ground up around specialized small language models and agentic systems, potentially offering lower latency, better edge performance, and more adaptive threat detection. - **Stealth Mode & First-Mover**: Operating in stealth allows the company to develop technology without competitive pressure, and its focus on agentic systems for security is a relatively new and high-value niche. - **Compliance Ready**: The company has achieved SOC 2 compliance, a critical trust signal for enterprise customers. ## Strategic Focus - **Product Development**: Completing the development and launch of its AI-native security platform, with a focus on real-time inference, policy enforcement, and agent orchestration. - **Team Building**: Scaling the engineering and AI teams, as evidenced by active job postings for Backend Engineers and an AI Lead. - **Market Entry**: Transitioning from stealth to a public launch, likely targeting enterprise clients in need of advanced network security. ## Why Work Here - **High-Impact Role**: Employees will be building core infrastructure and AI models from the ground up in a well-funded, early-stage startup. The roles offer ownership over critical system components (policy management, real-time decision workflows, agent orchestration). - **Cutting-Edge Tech Stack**: Work with specialized LLMs, agentic systems, graph databases, and real-time security pipelines — an attractive combination for engineers interested in AI and security. - **Hybrid & Remote Flexibility**: The company offers a hybrid workspace (typical on-site time required) and roles are listed as "In-Office or Remote," providing flexibility for the right candidates. - **Location**: Based in Saratoga, CA (Silicon Valley), with roles in San Jose, offering access to a major tech hub. - **Culture**: As a stealth startup with a clear vision, the culture is likely fast-paced, mission-driven, and engineering-focused. ## Sources 1. [builtin.com](https://builtin.com/company/protocol-nine-inc) 2. [builtin.com (Jobs)](https://builtin.com/company/protocol-nine-inc/jobs) 3. [strike.fyi](https://strike.fyi/c/protocolnine-com) 4. [filingflow.app](https://filingflow.app/companies/0002127845) 5. [filingflow.app (Form D)](https://filingflow.app/filings/0002127845-26-000001) ## Other roles at protocolnine.com - [AI Lead](https://feeny.ai/job/ai-lead-protocolnine-com-san-jose-kzk3sxe01hcj) — San Jose, CA