Senior Engineer, Full Stack - Pentest Experience

Get to Know Us

Horizon3 is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find and fix and verify exploitable attack vectors before criminals exploit them. Our flagship product, the NodeZeroTM platform, delivers production-safe autonomous pentests and other key assessment operations that scale across the largest internal, external, cloud, and hybrid cloud environments. NodeZero has been adopted by organizations of all sizes, from small educational institutions to government agencies and Global 100 enterprises. It is used by ITOps/SecOps teams, consulting pentesters, and MSSPs and MSPs. 

We are a fusion of former U.S. Special Operations cyber operators, startup engineers, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools, false positives resulting in alert fatigue, blind spots, "checkbox” security culture, cybersecurity skills shortage, and the long lead time and expense of hiring outside consultants. Collectively, we are a team of learn it alls, committed to a culture of respect, collaboration, ownership, and results.

What You’ll Do

We are hiring Senior Full Stack Engineers to join our team and help build product experiences that enable customers to understand, prioritize, and act on risk in their environments. This role is for a strong senior engineer who can own meaningful product work end-to-end across both backend and frontend systems, partnering closely with Product, Design, and peer engineers to deliver outstanding customer-facing outcomes.

The right candidate will be comfortable moving between backend services and modern frontend application development. This role will be approximately 80% backend focused and 20% frontend focused. You should be able to scope and drive work independently, proactively identify risks and tradeoffs, and help raise the bar for the engineers around them through strong execution, code reviews, and collaborative problem solving.

What You’ll Be Responsible For

• Build and ship world-class product capabilities spanning backend services, APIs, and modern web application interfaces.

• Own moderate-to-large projects end-to-end, including scoping, technical design, implementation, rollout, and iteration.

• Help implement user-facing experiences that are clear, maintainable, performant, and aligned with product requirements and design direction.

• Partner closely with Product, Design, and adjacent engineering teams to deliver cross-functional initiatives.

• Proactively identify and resolve technical risks, blockers, and mis-scoped work before they become larger delivery issues.

• Communicate technical topics clearly to both technical and non-technical audiences, including tradeoffs, delivery risks, and implementation choices.

• Contribute to architectural and design discussions with a strong sense for maintainability, operability, and long-term team productivity.

• Write high-quality code, tests, and technical documentation, and provide strong code reviews that improve the team’s overall output.

• Support and mentor less experienced engineers through thoughtful feedback, onboarding support, and day-to-day collaboration.

• Help improve engineering quality, team execution, and the product experience through a strong sense of ownership and continuous improvement.

What You’ll Bring

• Strong professional experience building and operating production software across both backend and frontend layers.

• Experience developing backend services in one or more modern languages such as Go, Rust, Python, Java, TypeScript, or similar.

• Experience building frontend applications with modern frameworks such as React, Angular, or similar.

• Strong understanding of APIs, service-oriented architectures, data modeling, and the engineering tradeoffs involved in building scalable product systems.

• Ability to independently drive substantial work from vague problem statement through delivery, while coordinating effectively with cross-functional stakeholders.

• Strong written and verbal communication skills, including the ability to explain technical decisions and tradeoffs clearly.

• A track record of strong engineering execution, sound technical judgment, and pragmatic problem solving under ambiguity.

• Experience mentoring other engineers through code reviews, design collaboration, and technical guidance.

• Product-minded thinking and a focus on building experiences that improve customer outcomes.

• Comfort working across multiple workstreams and balancing competing priorities with clarity and ownership.

Required Education/ Experience

• Bachelor’s degree in Computer Science, Computer Engineering, or a related field, or equivalent practical experience.

• 6+ years of professional software engineering experience.

• Experience building backend services using at least one modern language, such as Python, Go, Java, TypeScript, or similar.

• Experience building frontend applications using modern frameworks such as Angular or React

• Experience working with SQL base relational databases in production.

• Experience building backend services on a cloud platform (AWS, GCP, or Azure), and familiarity with Docker and containerized applications.

Preferred Education/ Experience

You don’t need all of these, but experience in some of the following will help you be successful quickly:

• Experience with PostgreSQL and performance tuning for large datasets.

• Experience with graph databases such as Neo4j or interest in learning them.

• Experience building or consuming GraphQL backends.

• Experience with ETL pipelines and data processing tools (e.g., Airflow-like frameworks, custom ETL jobs, or similar)..

• Experience with observability stacks (e.g., Datadog, Prometheus, Grafana) and instrumentation of services.

• Experience in cybersecurity, vulnerability management, security analytics, security data platforms, or adjacent domains

Required Tech Stack Experience

• Backend development in one or more of: Go, Rust, Python, Java, TypeScript, or similar.

• Frontend development using modern JavaScript/TypeScript in frameworks such as React, Angular, or similar.

• Designing and operating APIs, services, and asynchronous or event-driven systems.

• Data modeling and persistence layers for product-grade backend systems.

• Cloud-native application development and deployment patterns.

• Observability, reliability, and operational best practices for production services.

• Technical design documents, architectural proposals, and engineering standards that help teams build consistently and effectively.

What Sets You Apart?

• Experience building products or platforms in vulnerability management, exposure management, security telemetry, or related cybersecurity domains

• Familiarity with risk scoring, prioritization systems, or data-intensive backend workflows

• Experience partnering closely with product managers to define and sequence an MVP without painting the team into a corner.

• Experience helping define technical standards or practices adopted beyond your immediate team.

• A track record of shaping technical direction more broadly across an organization, with influence extending beyond a single team or domain.

Travel Required

We are a fully remote company, and this job may require up to 10% of travel to be successful. We meet as a team for project kicks offs and as a company annually. These in-person meetings are crucial to building a product, team, and culture we all can be proud of.

Perks of Horizon3

• Inclusive Team: We value diversity and promote an inclusive culture where everyone can thrive.

• Growth Opportunities: Be part of a dynamic and growing team with numerous career development opportunities.

• Innovative Culture: Work in a collaborative environment that encourages creativity and out-of-the-box thinking.

• Hybrid & Remote Work: We embrace a mix of remote and hybrid work models depending on role and location, including our Chicago office, where some roles require regular in-office presence.

• Competitive Compensation: We offer competitive salary, equity and benefits. Our benefits include health, vision & dental insurance for you and your family, a flexible vacation policy, and generous parental leave.

Compensation and Values

At Horizon3, we believe that our people are our greatest asset, and our compensation philosophy reflects this core value. We are committed to fostering an environment where all employees feel valued, respected, and rewarded for their contributions. Our compensation structure is designed to be fair, competitive, and transparent, ensuring that every team member is recognized and compensated equitably across roles, levels, and locations.

In accordance with various State’s transparency regulations, we provide the following salary range information for this position:

• Base salary range: $170,000 - $235,000 annually. The exact salary will be determined based on the selected candidate’s location, qualifications, experience, and relevant skills.

• Additional compensation: All full-time roles are eligible for an equity package in the form of stock options.

You Belong Here

Horizon3 is not just an equal opportunity employer - we are a community that values diversity, equity, and inclusion as fundamental principles of our culture and success. We are dedicated to fostering a workplace where everyone feels welcome and respected, regardless of race, color, religion, sex, national origin, age, disability, veteran status, sexual orientation, gender identity or expression, genetic information, marital status, or any other legally protected status by law.

Our commitment to diversity and inclusion means we strive to attract, develop, and retain a workforce that reflects the varied communities we serve. We believe that diverse perspectives drive innovation and strengthen our ability to create cutting-edge cybersecurity solutions. At Horizon3, every team member is valued and supported in an environment that encourages personal and professional growth.

We welcome candidates from all backgrounds and experiences, and we encourage all qualified individuals to apply. Come be a part of Horizon3, where your unique contributions are recognized, and your potential is limitless.

Other Duties

Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee. Duties, responsibilities, and activities may change at any time with or without notice. 

Application Note

In any materials you submit, you may redact or remove age-identifying information such as age, date of birth, or dates of school attendance or graduation. You will not be penalized for redacting or removing this information.