Back End Engineer

Horizon3 AI • Full-time • Remote (United States) • 12h ago

Get to Know Us

Horizon3.ai is a fast-growing, remote cybersecurity company dedicated to the mission of enabling organizations to proactively find, 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 IT Ops/SecOps teams, consulting pentesters, and MSSPs and MSPs.

We are a fusion of former U.S. Special Operations cyber operators, startup engineers & operators, and formerly frustrated cybersecurity practitioners. We're committed to helping solve our common security problems: ineffective security tools and 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.

As a remote first company, we require minimum 25Mbps consumer grade broadband connection.

Role Overview

We’re looking for a Backend Engineer to join our Application Platform Team (APT). APT owns cross-cutting platform features for the Horizon3.ai engineering team, and has a mandate to build out a world-class application platform which is reliable, scalable, and performant. As a Backend Engineer, you’ll help build and improve the backend systems and APIs that power NodeZero’s production-scale pentesting and reporting. You’ll work alongside experienced engineers to implement features, improve stability and performance, and make it easier for other Horizon3 teams to build on the platform.

This description reflects a mid level role: you’ll have meaningful ownership of components and projects, with strong mentorship and support from senior engineers and managers.

What You’ll Do

Responsibilities:

Build and enhance backend services that power NodeZero, with a focus on:
- ETL jobs and data pipelines used to process and analyze large graph and relational datasets.
- GraphQL APIs used by customer-facing features and internal tools (such as authentication, our internal management portal, reporting flows, and more).
- Improving the entrypoint to NodeZero, ensuring NodeZero runs seamlessly on various operating systems and provides improved observability into customer faced issues on installation process.
Implement and evolve backend APIs in GraphQL and Python to support:
- Internal tools that enable managing customer accounts and operations at scale
- Product features that rely on reliable, performant data access.
Help build foundational integrations platform
- Be involved in a new initiative to help scale Horizon3’s ability to integrate a large number of new partners.
- Help improve developer experience and API quality and operational readiness to ensure partner integrations are seamless.
Collaborate closely with other teams:
- Partner with product, frontend, and other engineering squads to ship user-facing improvements.
- Work with on-call and support engineers to debug production issues and improve reliability.
Contribute to platform performance and stability, including:
- Improving ETL and post-ETL performance around attack vectors and large customer environments.
- Enhancing observability and monitoring for runner queues, ETL jobs, and core APIs.
- Attack vector and asset graph processing.
- Platform features like runner queues, customer entitlements, and client migrations.
Participate in code reviews, testing, and documentation, helping raise the quality bar across the team.

What You’ll Bring

Ownership mindset at the feature/component level:
- You can take a scoped project from design discussion through implementation, testing, and rollout with guidance.
- You’re comfortable asking for help early when requirements or tradeoffs are unclear.
Strong collaboration skills:
- Clear, concise written and verbal communication.
- Ability to work effectively with designers, frontend engineers, product, and customer-facing teams.
Growth and learning orientation:
- Curiosity about how distributed systems, ETL pipelines, and APIs come together to support a complex SaaS product.
- Willingness to learn from senior engineers and to work in areas that might be new to you (e.g., graph databases, large-scale ETL, or advanced observability).
Attention to quality:
- You care about testing, clear documentation, and building systems that are debuggable and observable in production.
- You’re comfortable iterating quickly while still keeping reliability in mind.

Required Education/ Experience

Bachelor’s degree in Computer Science, Computer Engineering, or a related field, or equivalent practical experience.
1–4 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 working with SQL and at least one relational database 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 ramp faster on the Application Platform Team:

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 working on platform or infrastructure-facing teams, building capabilities that other engineering teams use.
Experience with observability stacks (e.g., Datadog, Prometheus, Grafana) and instrumentation of services.

Travel Required

We are a fully remote company with a strong preference for candidates in the Bay Area. This job may require up to 5% of travel to be successful.

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: $130,000 - $190,000 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.

Perks of Horizon3.ai

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.
Remote Work: We are a 100% remote company. Enjoy the flexibility to work in the way that supports you and brings out your best.
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.

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, hair length 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

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