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For Companies At a Glance
- Tasks: Design and optimise security software using Rust, ensuring performance and reliability.
- Company: Join Harmonic Security, a cutting-edge AI cybersecurity firm.
- Benefits: Competitive pay, equity, flexible work, and generous PTO.
- Why this job: Make a real impact in cybersecurity while working with innovative technology.
- Qualifications: Experience in Rust or C++, with a passion for systems programming.
- Other info: Be part of a small, dynamic team that values creativity and growth.
The predicted salary is between 36000 - 60000 ÂŁ per year.
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.
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 hands‑on systems engineer with deep expertise in Rust (or C++ with a strong willingness to learn and embrace Rust as your primary language) to help us build and evolve security critical client software. You will work on low level security agents and cross platform components that run on user devices, with a strong emphasis on robustness, performance and security. Your work will power core functionality in how we collect signals, and manage on‑device controls for app usage and data movement. You will join a fast‑moving team that ships frequently and cares about correctness, observability and maintainability.
What You’ll Do
- Design, implement, and optimise endpoint security agent components in Rust, targeting desktop and/or server platforms (Windows, macOS, Linux)
- Build robust tests, validation tooling and deployment mechanisms for client facing releases that impact our customers in their everyday work
- Conduct exploratory technical research to understand the art of the possible and how to best approach implementation of new product features
- Investigate and resolve platform specific issues with precision and speed
- Work closely with security engineers, backend engineers, and product stakeholders to shape technical requirements
What Success Looks Like
- You’ve shipped production Rust or C++ code that runs safely and efficiently across platforms
- Your components are well tested, observable, and resilient to partial failures or bad input
- You identify performance or architectural bottlenecks before they reach users
- You actively reduce complexity in critical code paths without compromising clarity or functionality
- You consistently deliver high‑quality changes on a tight feedback loop, including regression‑safe updates
Requirements
- Strong hands‑on experience with Rust (or C++ with a strong willingness to learn Rust) in production systems
- Solid grasp of systems programming concepts: memory safety, lifetimes, threads, channels, error handling, IPC
- Familiarity with platform APIs and subsystems on Linux, Windows and macOS
- Experience building CI‑tested, reproducible builds for native applications
- Proficiency with common developer tooling: Git, code review, CI pipelines, structured logging, crash analytics
- Networking skills and security fundamentals is a plus
What you Bring
- Strong hands‑on experience with Rust (or C++ with a strong willingness to learn Rust) in production systems
- Solid grasp of systems programming concepts: memory safety, lifetimes, threads, channels, error handling, IPC
- Familiarity with platform APIs and subsystems on Linux, Windows and macOS
- Experience building CI‑tested, reproducible builds for native applications
- Proficiency with common developer tooling: Git, code review, CI pipelines, structured logging, crash analytics
- Networking skills and security fundamentals is a plus
You Might Be a Fit if You...
- Have a strong development background and a rigorous approach to testing and validation
- Relish the prospect of writing code that will run on millions of devices and needs to be reliable and performant around the clock
- Enjoy working close to the OS and care deeply about software performance, correctness and safety. Previous Kernel or system‑level development experience is a great nice‑to‑have
- Can build and ship reliable systems fast, with a sharp eye for edge cases and long term impact and maintainability
- Learn quickly and independently, with great attention to detail and high standards
- Have made contributions to open‑source Rust (or C++) projects or RFCs
- Believe that good tooling and documentation are part of engineering, not afterthoughts
- Thrive in fast‑paced startup environments where ambiguity is the norm
- See AI as a tool to help you build smarter, faster and better
Benefits
- 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
Seniority level: Mid‑Senior level
Employment type: Full‑time
Job function: Other IT Services and IT Consulting
Principal Systems Engineer employer: Harmonic Security
Contact Detail:
Harmonic Security Recruiting Team
StudySmarter Expert Advice 🤫
We think this is how you could land Principal Systems Engineer
✨Tip Number 1
Network like a pro! Reach out to folks in the industry, especially those at Harmonic Security. A friendly chat can open doors that applications alone can't.
✨Tip Number 2
Show off your skills! If you’ve got a GitHub or portfolio showcasing your Rust or C++ projects, make sure to share it during interviews. It’s a great way to demonstrate your hands-on experience.
✨Tip Number 3
Prepare for technical interviews by brushing up on systems programming concepts. Be ready to discuss memory safety, error handling, and how you tackle performance issues in your code.
✨Tip Number 4
Don’t forget to apply through our website! It’s the best way to ensure your application gets seen by the right people. Plus, it shows you’re genuinely interested in joining our team.
We think you need these skills to ace Principal Systems Engineer
Some tips for your application 🫡
Tailor Your CV: Make sure your CV reflects the skills and experiences that align with the Principal Systems Engineer role. Highlight your hands-on experience with Rust or C++, and don’t forget to mention any relevant projects that showcase your systems programming expertise.
Craft a Compelling Cover Letter: Your cover letter is your chance to shine! Use it to tell us why you’re passionate about working at Harmonic Security and how your background makes you a perfect fit for our team. Be genuine and let your personality come through!
Showcase Your Problem-Solving Skills: In your application, give examples of how you've tackled complex problems in past projects. We love candidates who can think critically and approach challenges with creativity, especially when it comes to security and performance.
Apply Through Our Website: We encourage you to apply directly through our website. It’s the best way for us to receive your application and ensures you’re considered for the role. Plus, it shows us you’re keen on joining our team!
How to prepare for a job interview at Harmonic Security
✨Know Your Rust (or C++) Inside Out
Make sure you brush up on your Rust or C++ skills before the interview. Be ready to discuss your past projects and how you've used these languages in production systems. They’ll want to see your understanding of memory safety, error handling, and other systems programming concepts.
✨Showcase Your Problem-Solving Skills
Prepare to talk about specific challenges you've faced in previous roles, especially those related to performance or architectural bottlenecks. Think of examples where you identified issues and how you resolved them quickly and effectively.
✨Familiarise Yourself with Their Tech Stack
Research Harmonic Security’s products and the technologies they use. Understanding their approach to security and AI tools will help you align your answers with their goals. It shows that you’re genuinely interested in the role and the company.
✨Emphasise Collaboration and Communication
Since the role involves working closely with various teams, be prepared to discuss how you’ve collaborated with others in the past. Highlight your experience in sharing ideas and feedback, as well as how you’ve contributed to a team environment.
