Back End Engineer

Get to Know Us Horizon3.ai http://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 http://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 comforta