As a Software Engineer at Harmonic Security, your primary focus will be designing, building, and maintaining the core software products that empower enterprises to secure their sensitive data. You will work across the software development lifecycle, taking features from initial concept and design through to deployment and monitoring.

Collaboration is central to this role. You will partner closely with product managers to define feature requirements, work alongside systems engineers to integrate frontend interfaces with deep security pipelines, and collaborate with security researchers to ensure the platform accurately visualizes complex threat data. You will play an active role in architectural discussions, helping to set coding standards, design API contracts, and select technologies that ensure the platform remains scalable and secure.

Additionally, you will be expected to continuously improve the engineering codebase. This includes refactoring legacy components, optimizing application performance, writing comprehensive unit and integration tests, and participating in constructive code reviews. Your day-to-day efforts will directly influence the product's usability, reliability, and overall security posture, helping Harmonic Security maintain its position as a trusted leader in data security.

To be competitive for the Software Engineer position at Harmonic Security, you should possess a strong foundation in modern software engineering practices, with a particular emphasis on frontend development and system architecture.

Technical Skills

• Core Frontend Technologies – Deep proficiency in React, JavaScript, TypeScript, and CSS is essential. You should be highly comfortable building complex, interactive interfaces from scratch.
• API & Data Design – Strong experience designing RESTful APIs, defining JSON schemas, and structuring application state.
• Testing & Tooling – Experience writing clean, maintainable tests (unit, integration, and end-to-end) and using modern build tools (such as Vite, Webpack, or ESBuild).

Experience & Soft Skills

• Professional Experience – Typically, successful candidates have several years of professional software engineering experience, ideally within a fast-paced product engineering team or a high-growth startup environment.
• Pragmatic Problem-Solving – The ability to balance speed of delivery with code quality, making smart trade-offs when necessary.
• Clear Communication – Strong verbal and written communication skills, with the ability to explain complex technical concepts to both technical and non-technical stakeholders.

Nice-to-Have Qualifications

• Cybersecurity Domain Knowledge – Prior experience working in cybersecurity, data loss prevention (DLP), or cloud security platforms is highly advantageous.
• Full-Stack Familiarity – Experience working with backend languages (such as Python, Go, or Node.js) and database technologies is a strong plus.

Q: How technical is the interview process at Harmonic Security? A: The process is highly practical and focused on real-world engineering tasks. Rather than testing you on abstract algorithmic puzzles, the team evaluates your core coding skills, your understanding of React and CSS, and your ability to design clean API contracts and data structures.

Q: What is the company culture like for engineers? A: Harmonic Security has a collaborative, high-ownership culture typical of an ambitious, fast-growing startup. Engineers are encouraged to take initiative, contribute to product decisions, and collaborate closely across teams to solve complex data security challenges.

Q: Do I need a background in cybersecurity to apply? A: While prior experience in cybersecurity or data security is a nice-to-have, it is not a strict requirement. The team highly values strong software engineering fundamentals, architectural curiosity, and a willingness to learn the domain quickly.

Q: Is there an in-person component to the interview process? A: Yes, depending on your location. For candidates applying to roles near regional hubs, such as London, the process often includes an in-person stage at the Old Street office for the whiteboarding and cultural fit sessions. For other locations, these stages are conducted via structured video loops.

• Think out loud during the design phase: In the system design and whiteboarding exercises, the interviewers care deeply about your thought process. Talk through your assumptions, explain why you are choosing a particular data structure, and discuss any trade-offs you are making in real time.
• Be honest about past project failures: When discussing a project you are proud of, do not hesitate to talk about what went wrong. Showing that you can identify architectural mistakes and explain how you would fix them today is a massive indicator of senior engineering maturity.
• Brush up on CSS fundamentals: Do not overlook core CSS concepts. You may be asked direct questions about positioning, layout models, and responsive design, so make sure you can explain these concepts clearly without relying on utility frameworks.

• Align your answers with the startup environment: Emphasize your ability to work independently, handle ambiguity, and adapt to changing product requirements. Showing that you are proactive and customer-focused will resonate strongly with the hiring team.

The Software Engineer position at Harmonic Security represents an extraordinary opportunity to work at the absolute cutting edge of cybersecurity and artificial intelligence. By joining this talented and ambitious team, you will build the critical user interfaces and robust data systems that enable enterprises to safely harness the power of generative AI. The work you do will directly impact the security posture of organizations worldwide, making this a role of high visibility and significant strategic value.

As you prepare for your interviews, focus your efforts on mastering the core technical evaluation areas: deep frontend fundamentals, clean API and data structure design, and the ability to retrospectively analyze your past engineering decisions. Approach each conversation with curiosity, clarity, and a collaborative spirit, as the team values strong communication and cultural alignment just as highly as technical execution.

The salary data above outlines the typical compensation ranges for engineering roles at Harmonic Security across different experience levels and locations. When preparing your compensation expectations, consider how your unique blend of skills, domain expertise, and professional experience aligns with these competitive benchmarks.

To gain even deeper insights into the hiring process, read detailed candidate reviews, and access additional preparation resources, explore the comprehensive community-driven data available on Dataford. With focused preparation and a clear understanding of what the team is looking for, you are well-positioned to showcase your skills and secure your place at Harmonic Security. Good luck!