Note: The job is a remote job and is open to candidates in USA. Horizon3 is a cybersecurity company whose NodeZero platform helps organizations identify and verify exploitable attack vectors. The Senior Backend Engineer, Integrations will build and operate customer-facing APIs, integration infrastructure, and MCP capabilities that connect NodeZero with security and IT tools.

Responsibilities

• Design and implement backend APIs in GraphQL — including federated subgraph development, schema evolution, and multi-account query scoping for MSSP and multi-subsidiary customers
• Build and extend the Integration Router: connector libraries, workflow configuration, secrets management, vendor adapters, and Kafka-triggered dispatch services
• Own production reliability for API and integration services: monitoring, alerting, deployment, vendor API drift, rate limits, retries, and safe failure handling
• Contribute to the MCP platform and OAuth proxy layer, including tool authentication and agentic workflow support
• Contribute production code that sets the standard for design quality, code quality, and operational rigor
• Collaborate with frontend engineers, product managers, and security-domain teams (particularly the Pentest Data Platform) to deliver integrated customer experiences
• Mentor junior and mid-level engineers on the team as it scales

Skills

• Ability to own and manage concurrent initiatives, with strong judgment in prioritization and time management
• Self-directed and driven — capable of conceiving and implementing solutions independently and as part of a team
• A strong desire to continuously learn new technologies in a fast-paced Agile environment
• Excellent analytical and problem-solving skills, with attention to detail and a high bar for quality
• Strong technical documentation ability to support an external developer audience
• Effective communication and collaboration across engineering, product, and design
• Interest in mentoring junior and mid-level engineers as the team grows
• Bachelor's Degree in Computer Science, Computer Engineering, or a related field
• 7+ years of professional software engineering experience using modern object-oriented or functional languages (Python, Go, TypeScript, Java, Scala, C++, etc.)
• Experience building production applications on cloud platforms (AWS, Azure, GCP) using Docker and Kubernetes
• Expert proficiency in SQL, and experience with relational (PostgreSQL) and graph (Neo4j) database architectures
• Hands-on experience building GraphQL backends, including federated graph architectures and schema evolution patterns
• Experience designing and operating public API platforms — versioning, developer documentation, permission models, and multi-tenant access
• Experience building or operating an integrations platform with reusable connector patterns, event-driven workflows (Kafka or similar), and asynchronous execution
• Familiarity with OAuth/OIDC, service accounts, or machine identity patterns for programmatic API access
• Experience integrating with third-party security or IT platforms — SIEMs, EDR tools, ticketing systems (e.g., CrowdStrike, Splunk, ServiceNow, Jira, Palo Alto), or workflow automation platforms
• Experience with MCP, agentic frameworks, or other tool-protocol ecosystems
• Production reliability experience: observability tooling (Datadog or similar), on-call ownership, vendor API drift handling, and safe failure design
• Experience with customer-facing developer surfaces: CLI tooling, SDKs, or developer portals

Benefits

• Career development opportunities.
• A collaborative environment that encourages creativity and out-of-the-box thinking.
• A mix of remote and hybrid work models depending on role and location, including the Chicago office, where some roles require regular in-office presence.
• Health, vision & dental insurance for you and your family.
• A flexible vacation policy.
• Generous parental leave.
• All full-time roles are eligible for an equity package in the form of stock options.

Company Overview