DevOps Engineer in London

About Harmonic Security

Harmonic Security lets teams adopt AI tools safely by protecting sensitive data in real time with minimal effort. It gives enterprises full control and stops leaks so that their teams can innovate confidently. We are led by cybersecurity experts and backed by top investors including N47, Ten Eleven Ventures, and In-Q-Tel.

As Harmonic's product and customer footprint grow, the reliability, security, and developer experience of our underlying platform become mission-critical. This role exists to build and operate the infrastructure that makes safe, real-time AI adoption possible at scale. As a Senior DevOps Engineer, you'll design the automation, deployment pipelines, and cloud architecture that power our product every day — creating a resilient, low-friction platform that engineers trust and customers depend on. This is a hands-on opportunity to shape the technical foundations of a category-defining security company from the inside out.

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

The Senior DevOps Engineer is responsible for designing, building and maintaining the highly scalable infrastructure that powers our applications. This role is a blend of automation, infrastructure design and CI/CD pipeline development.

What you'll do

• Your primary focus is the automation and standardisation of our cloud infrastructure and deployment processes.
• Develop reusable modules to enforce consistency and best practices across all environments.
• Design and implement highly available and fault-tolerant architectures on AWS utilising multiple AZs and regions.
• Build, maintain, and optimise CI/CD pipelines using GitLab CI/CD. Manage and configure GitLab Runners (specifically on Docker or AWS EC2/ECS) for scalable and efficient job execution, ensuring fast feedback loops for developers.

What success looks like

• You evangelise and implement DevOps best practices, including shift-left security, monitoring, alerting and logging.
• The platform provides an outstanding experience with minimal friction for both the development and operations teams, allowing everyone to do their best work.
• Highly available, well maintained platform backed by repeatable processes that allow us to meet and exceed the highest standards for security and resilience.

What you bring

• 5+ years in a DevOps role.
• Experience with infrastructure as code tooling (preferably Terraform/OpenTofu).
• Experience with cloud services (preferably AWS).
• Understanding of networking and web applications.
• Knowledge of Docker and container orchestration platforms.
• Knowledge of Linux/Unix based operating systems.
• Experience of CI/CD tooling (GitLab, GitHub, etc.).
• Experience of troubleshooting issues with infrastructure and web applications.
• Proficient in one or more scripting languages (Bash, Python etc.).
• Experience with monitoring and log management tooling (Prometheus, Grafana, ELK, CloudWatch etc.).
• Experience working within a fast moving software development organisation.

You might be a fit if you...

• You have a solid understanding of development processes. We think you may have been a developer in the past who has made the move to DevOps - we think you are more Dev than Ops!
• You love the idea of working in a role that focuses on building and maintaining resilient and modern infrastructure that can deal with huge workloads.
• Thrive in fast-paced startup environments where ambiguity is the norm.
• See AI as a tool to help you build smarter, faster and better.

Why join us

• This isn't just a job; it's an opportunity to be part of a team that is redefining cybersecurity. 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.
• Competitive pay and meaningful equity with a direct stake in Harmonic's success.
• Comprehensive benefits, pension plan, generous PTO, and flexible hybrid work.
• A small, passionate team that values transparency, creativity, and learning.
• Thoughtful leadership that cares deeply about growth, impact, and people.
• Annual global offsites (past trips include Lisbon and Nashville).
• The chance to directly shape both our product and our culture as we build a category-defining company.

Harmonic's core values

• Flourish in the Unknown: We relish being thrown into new, unfamiliar situations that require initiative and rapid decision-making. We orient ourselves quickly and deliver results with minimal guidance.
• Never Full: We never hesitate to raise our hands and take on challenges to assist those in need. We hunger for opportunities to learn and do more.
• Perfect Harmony: We have a genuine willingness to assist and support one another to create cohesion and unity. We foster success through collaboration and honest sharing of feedback and ideas, enabling everyone to grow and produce their best work.