At a Glance
- Tasks: Lead the development of security-critical software for AI-driven data protection.
- Company: Join a dynamic cybersecurity startup shaping the future of AI security.
- Benefits: Competitive salary, equity options, and a chance to work with industry leaders.
- Other info: Work in a collaborative environment with excellent growth opportunities.
- Why this job: Make a real impact in a mission-critical role at the forefront of AI security.
- Qualifications: Experience in Rust or C++, with a focus on security-critical software development.
The predicted salary is between 150000 - 195000 £ per year.
Harmonic Security Inc. is a ~$25M Series A cybersecurity startup backed by Next47 and Ten Eleven Ventures, defining the AI security category. They build zero-touch data protection platforms that allow enterprises to safely adopt AI tools by protecting sensitive data at the endpoint in real time with sub-500ms inference.
As a Principal Systems Engineer at Harmonic Security Inc., you will lead the development of low-level, security-critical endpoint agent software. Operating across Windows, macOS, and Linux, you’ll build high-performance Rust components that monitor and protect data movement. This is a mission-critical role defining how enterprises secure their AI-driven future at the OS level.
Location: London, UK
Why this role is remarkable:
- Build a category-defining product at a $25M Series A startup founded by seasoned cybersecurity leaders who previously built Digital Shadows.
- Work at the cutting edge of AI-first security, writing high-performance Rust code that runs on millions of devices with sub-500ms latency.
- High-impact leadership role reporting to the VP of Engineering, influencing the core architecture and technical direction of the entire endpoint platform.
What You Will Do:
- Design and optimize security-critical endpoint agent components in Rust, ensuring reliability across Windows, macOS, and Linux platforms.
- Architect foundational agent systems for signal collection and on-device controls, setting the technical bar for correctness, performance, and safety.
- Work closely with backend and security engineers to bridge low-level system signals with enterprise-grade policy enforcement and real-time observability.
The ideal candidate:
- Strong production experience in Rust or C++, with a deep understanding of memory safety, concurrency, and systems programming fundamentals.
- Proven track record building security-critical client software like EDR, XDR, or DLP agents across multiple operating systems.
- A proactive, AI-first mindset, comfortable using tools like Cursor or Claude to accelerate development and solve complex, low-level technical challenges.
Principal Systems Engineer (£150k-£195k + Equity) at Harmonic Security Inc. employer: Jack & Jill
Harmonic Security Inc. is an exceptional employer, offering a unique opportunity to work at the forefront of AI-driven cybersecurity in London. With a strong focus on innovation and employee growth, the company fosters a collaborative work culture where your contributions directly impact the development of cutting-edge security solutions. Enjoy competitive compensation, equity options, and the chance to lead critical projects within a dynamic startup environment backed by industry leaders.
StudySmarter Expert Advice🤫
We think this is how you could land Principal Systems Engineer (£150k-£195k + Equity) at Harmonic Security Inc.
✨Get Involved in the Cybersecurity Community
Diving into the cybersecurity community is key for landing that full-time gig. Join forums like Reddit's r/cybersecurity or attend local meetups to connect with industry veterans and other job seekers. Networking is everything in this field—don’t just be a passive lurker!
✨Show Off Your Skills with Capture the Flag Competitions
Participate in Capture the Flag (CTF) competitions; these are not just a fun way to boost your skills but also a chance to showcase your talent to potential employers. Many companies, including Jack & Jill, love seeing candidates who actively engage in these challenges.
✨Tailor Your Online Presence
Make sure your LinkedIn and any professional profiles reflect your cybersecurity expertise. Share your projects, whether they’re personal or from a previous role, to catch the eye of hiring managers. This is how they’ll find your passion and commitment to the field!
✨Apply Directly Through Jack & Jill
Don’t forget to head straight to our website and check out any openings for cybersecurity roles at Jack & Jill. Applying directly can sometimes give you an edge, especially if you can mention that you've been following our work or engaging in the community.
We think you need these skills to ace Principal Systems Engineer (£150k-£195k + Equity) at Harmonic Security Inc.
Some tips for your application 🫡
Show off your technical skills:In cybersecurity, it's crucial to highlight your technical prowess. Make sure your CV showcases specific skills like network security, penetration testing, or threat analysis. If you have relevant certifications (like CEH or CISSP), pop those on the front page to grab attention!
Tailor your portfolio for the role:Even for a full-time role, a portfolio can set you apart. If you've worked on any cybersecurity projects—be it CTF challenges, security assessments, or research papers—include these in your application. This demonstrates not just your skills, but also your hands-on experience!
Use real-world examples:When writing your cover letter, don’t just stick to your qualifications. Share real-world examples of how you’ve tackled security issues or vulnerabilities. This gives the hiring team at Jack & Jill insight into your practical problem-solving abilities and makes your application memorable.
Demonstrate your passion for cybersecurity:Cybersecurity is an ever-evolving field, so show us that you’re always learning! Mention any recent courses, webinars, or industry events you’ve attended. This not only exhibits your enthusiasm but also signals to Jack & Jill that you’re committed to staying ahead in the game.
How to prepare for a job interview at Jack & Jill
✨Sharpen Your Technical Skills
For a role in cybersecurity, it’s essential to be up-to-date with the latest tools and techniques. Brush up on your knowledge of firewalls, intrusion detection systems, and vulnerability assessment tools. Be ready to discuss specific scenarios where you’ve applied these skills, as hands-on experience can really set us apart in interviews.
✨Prepare for Scenario-Based Questions
Expect the interviewers at Jack & Jill to throw in some hypothetical situations to see how you’d handle them. Think about common security breaches or incidents and be prepared to explain how you would respond. This not only shows your problem-solving skills but also your understanding of real-world cybersecurity challenges.
✨Highlight Your Certifications
Certifications like CompTIA Security+, CISSP, or CEH can give you a significant edge in a full-time role in cybersecurity. Make sure to mention these during your interview and be prepared to discuss what you learned through those certifications and how they relate to the position at Jack & Jill.
✨Show Your Passion for Cybersecurity
Since you’re going for a full-time gig, showing genuine enthusiasm for the field can make all the difference. Share any personal projects, blogs, or communities you’re part of that relate to cybersecurity. This not only showcases your passion but also your commitment to staying engaged in this ever-evolving field.
