---
title: 'Senior Backend Engineer at Harmonic Security, Inc'
canonical: 'https://feeny.ai/job/senior-backend-engineer-harmonic-security-inc-london-z4syq6kdgrq4'
type: 'job'
last_seen: '2026-09-16'
---

# Senior Backend Engineer at Harmonic Security, Inc

- **Company:** Harmonic Security, Inc
- **Location:** London, United Kingdom
- **Compensation:** £98k–£110k
- **Employment:** full-time
- **Work type:** hybrid
- **Posted:** 2026-07-09
- **Last confirmed live:** 2026-09-16
- **Apply:** https://jobs.ashbyhq.com/harmonic-security-inc/a380e159-ecd1-432d-ad67-6f227599e106

## Job description

AI is being run everywhere, by humans and agents. Harmonic Security governs all of it. The AI Governance and Control (AIGC) platform understands user / agent intent and data context in real time, giving security teams visibility and control across every tool and workflow so companies can move faster with AI while minimizing risk. We operate in one of the fastest-moving spaces in tech: the emerging intersection of AI and cybersecurity. It's a market still being defined, and we're among the first to build natively for it - protecting sensitive data in real time, at the endpoint, with minimal friction for the teams using it. Enterprises get full visibility and control. Their people get to innovate without guardrails slowing them down. Named to the Rising in Cyber 2026 list, Harmonic is gaining serious recognition and serious traction. We're led by deep cybersecurity expertise and backed by investors who know the space: N47, Ten Eleven Ventures, and In-Q-Tel. As AI adoption inside the enterprise accelerates, the ability to safely observe, control, and enforce policy in real time isn't a nice-to-have. It's mission-critical infrastructure. That's what we build.

How We Work: AI-First by Design Harmonic exists to help enterprises adopt AI safely and at scale. We hold ourselves to that same standard. Everyone here actively leverages AI tools to perform their best work — from deep research and writing to building robust processes and automating complex workflows. We expect every new hire to bring a genuine curiosity for AI and a commitment to using it to work smarter, faster, and with greater creativity. For some, this involves tinkering and remaining open to emerging tools; for others, it means architecting entirely new systems with AI at the core. We will be transparent about expectations for every role and provide the tools and support needed for you to thrive.

## About the Team

Our Product Delivery team is the engine that turns vision into impact. We ship early and often, getting valuable features into the hands of customers quickly and iterating from there. We work in the open by default, sharing progress and ideas, and we trust each other to own outcomes. We’re a small but mighty crew where every person plays a critical role and we’re committed to using AI to work smarter and faster.

## About the Role

We’re looking for a Backend Engineer who has an appreciation for all things security and system interconnectivity. This is a very hands-on technical role where you will be responsible for designing, building and maintaining scalable integrations between our core applications, identity providers and data security platforms.

## What You'll Do

- Own deliveries and features from start to finish
- Design, build, and own backend services in a microservices-based, event-driven architecture
- Implement core domain logic that drives key product workflows and system behavior
- Ingest and process high-volume usage and event data from customer-facing endpoints
- Build backend services that support operational, analytics, and reporting use cases
- Model, persist, and manage domain data, enabling querying, filtering, and lifecycle management
- Expose well-designed APIs and webhooks consumed by customers, UIs, and external systems
- Power customer-facing UI experiences by providing backend APIs for visibility, analytics, and configuration

## What You Bring

- 3–5+ years of professional software engineering experience building backend services and distributed systems in the Java ecosystem (Java, Spring Boot, Maven/Gradle)
- Strong understanding of event-driven architectures, asynchronous processing patterns, messaging systems, and distributed system design
- Proven experience designing and maintaining RESTful APIs, web hooks, and service-to-service integrations
- Comfortable operating in AWS, GCP, or Azure environments and working with modern observability tooling, logging, and monitoring platforms
- A track record of delivering performant, reliable and scalable applications
- Excellent collaboration and communication skills in cross-functional teams

You Might Be a Fit if You

- Have experience building products in cybersecurity, identity, governance, compliance, data protection, or enterprise SaaS environments
- You understand not just how to build systems, but why architectural decisions matter
- You can balance scalability, reliability, maintainability, and speed of execution
- You think critically about security, observability, and operational excellence from day one
- Love the idea of blending software development, distributed systems and data-intensive applications
- Strong familiarity with authentication and identity technologies such as OAuth, OpenID Connect (OIDC), SAML, SCIM, Entra ID (Azure AD), Okta, or other enterprise identity providers
- Thrive in fast-paced startup environments where ambiguity is the norm
- Enjoy shaping culture and engineering practices, not just writing code
- Leverage AI tools as an engineer to help you build smarter, faster and better

## Why Join Us

This isn't just a job - it's a chance to help define a category. Harmonic Security was named to the Rising in Cyber 2026 list, and we're just getting started. We're building at the intersection of AI and security, carving out an emerging market where the rules haven't been written yet, and the people who join now will write them. We believe today's talent is tomorrow's success, and we're committed to creating an environment where you can do the best work of your life.

- Recognized momentum - We made the Rising in Cyber 2026 list, a signal that the market is taking notice
- Rare market opportunity - Join early in a category-defining company at the convergence of AI and security, where your work directly shapes how enterprises tackle one of the biggest unsolved problems in tech
- Competitive pay and meaningful equity - A real stake in Harmonic's success, not a token gesture
- Comprehensive benefits - 401K, pension plan, generous PTO, and flexible hybrid work
- A small, high-trust team that values transparency, creativity, and continuous learning - no politics, no bureaucracy
- Thoughtful leadership - that cares deeply about your growth, not just your output
- Annual global off-sites - past trips include Lisbon, Portugal and Nashville, TN
- Real ownership - you'll shape the product, the culture, and the direction of the company from day one

Harmonic's Core Values 🌱 Flourish in the Unknown We embrace new, unfamiliar situations that require initiative and rapid decision-making. We orient ourselves quickly and deliver results with minimal guidance. 🔥 Never Full We raise our hands, take on challenges, and assist others whenever possible. We hunger for opportunities to learn and do more. 🤝 Perfect Harmony We support one another to create cohesion and unity. We collaborate openly, share feedback honestly, and help everyone produce their best work

## About Harmonic Security, Inc

## Company Overview
- **One-liner**: Harmonic Security provides an AI governance and control platform that gives enterprises real-time visibility and inline guardrails across browser, desktop, and AI agent surfaces to enable safe, fast AI adoption.
- **Entity Type**: Private (raised $24.5M total funding across Seed and Series A rounds)
- **Headquarters**: San Francisco, California, United States (with additional offices in London, UK)
- **Founded**: August 2023
- **Founders**: Alastair Paterson (CEO & Co-founder) and Mark Sutton (CTO & Co-founder)

## Core Business
- Primary industry: AI Governance and Security (Technology, Information and Internet)
- Target customers: Enterprise B2B, specifically security teams and IT administrators
- Mission: "To pave the way for secure AI adoption in enterprises, ensuring innovation thrives without compromise"

## Products & Services
- **Harmonic Security Platform**: A unified control plane covering four surfaces (browser extensions, desktop clients, MCP gateway, embedded AI copilots) that reads the intent and context of every AI interaction, applies policies inline in under 200 milliseconds, and coaches users in the moment without disrupting work.
- **MCP Gateway**: Governs agentic workflows at the Model Context Protocol layer, inspecting tool calls, scopes, and destructive actions even when no human is in the loop.
- **Browser Extension + Desktop Client**: Covers 1,000+ AI surfaces including ChatGPT, Claude Desktop, Cursor, Canva, Gamma, Grammarly, Google AI mode, and more. Detects sensitive data and enforces guardrails on end-to-end encrypted traffic that never passes through the corporate proxy.
- **Agent Governance**: Extends policies to autonomous AI agents that act independently, inspecting file reads, API calls, database writes, and email summaries.

## Market Standing
- **Valuation/Market Cap**: Not publicly disclosed
- **Key Metric**: Total funding $24.5M; LinkedIn-estimated annual revenue of $1.0M (may be a placeholder)
- **Notable Investors/Partners**: Ten Eleven Ventures (Alex Doll, Founder), René Bonvanie, Grant Whiting, Bryan Woolgar-O'Neil
- **Growth Signals**: 
  - RSA Innovation Sandbox Finalist in 2024
  - Launched MCP Gateway in October 2025
  - Landed Series A funding (July 2024)
  - Headcount of ~55 employees with consistent hiring across SF, London, and remote US
  - SOC 2 and GDPR certified; EU AI Act alignment

## Competitive Advantages
- **Intent-based detection, not keyword/regex**: Policies fire on the intent and context of prompts and agent actions rather than string matching, reducing false positives.
- **Covers the full AI surface**: Browser, desktop, MCP, and embedded copilots — including traffic and agents that network tools cannot see.
- **Inline guardrails in <200ms**: Real-time decisions that coach users or block actions without disrupting workflow.
- **Privacy-by-design**: Employee names can be masked, HR/Finance/Ops/Founders excluded from reporting, and the dataset is sanitized and frozen. Designed to avoid becoming surveillance.
- **Rapid deployment**: Minutes via MDM (Intune, JAMF, Kandji, Group Policy) with no proxy redesign or certificate gymnastics. Full AI inventory available on day one.
- **Agent-ready**: Governs autonomous AI workflows at the MCP and tool call level, not just human prompts.

## Strategic Focus
- Scaling enterprise adoption of AI governance for both human and agentic AI use
- Deepening MCP Gateway capabilities as AI agents become more prevalent
- Growing the platform's coverage to new AI surfaces and expanding data classification
- Maintaining leadership in the emerging AI Security category through continued product innovation and market education

## Why Work Here
- **Culture**: Small, senior team operating in high-trust, high-ownership mode. Real responsibility from day one. Values include "Flourish in the Unknown" (comfort with ambiguity), "Never Full" (hunger to learn and help), and "Perfect Harmony" (collaboration and honest feedback).
- **Work Policy**: Flexible hybrid — 3 days per week in the San Francisco office for US-based roles; London team also hybrid. Remote US roles available.
- **Benefits**: Competitive pay and meaningful equity; health, dental, and vision coverage; 401k matching; flexible time off; 25 days PTO (UK); pension plan matching (UK); Cycle to Work Scheme (UK). Annual global offsites (past locations include Lisbon and Nashville).
- **Engineering Culture**: Substance over hype; psychological safety and mutual respect; decisions made quickly; feedback direct; focus on building for high-stakes environments.
- **Growth**: Shape both the product and the category in a foundational moment for AI governance.

## Sources
1. [harmonic.security](https://www.harmonic.security/)
2. [harmonic.security/company/careers](https://www.harmonic.security/company/careers)
3. [harmonic.security/about](https://www.harmonic.security/about)
4. [linkedin.com/company/harmonic-security](https://www.linkedin.com/company/harmonic-security)
5. [builtin.com/company/harmonic-security](https://builtin.com/company/harmonic-security)

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