[Remote] Back End Engineer

Note: The job is a remote job and is open to candidates in USA. Horizon3.ai is a fast-growing, remote cybersecurity company dedicated to enabling organizations to proactively find, fix, and verify exploitable attack vectors. The Backend Engineer will join the Application Platform Team to build and improve backend systems and APIs for the NodeZero platform, ensuring reliability, scalability, and performance. 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 scaleProduct features that rely on reliable, performant data access.Help build foundational integrations platformBe 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 Skills 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 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 Benefits Health, vision & dental insurance for you and your family Flexible vacation policy Generous parental leave Company Overview Horizon3.ai offers an autonomous penetration testing platform that helps organizations proactively find and fix security vulnerabilities. It was founded in 2019, and is headquartered in San Francisco, California, USA, with a workforce of 201-500 employees. Its website is