Senior Full-Stack Engineer, Autonomous Defense

The role

You will build the platform that NodeZero's defensive agents run on. This includes owning the runtime, tool layer, orchestration, connector framework, and observability and UI.

What you will do

• Build and own the agent execution runtime
• Design and implement the tool layer that agents act through
• Build the connector framework for third-party security control planes
• Implement the safe-change pipeline
• Build the operator-facing front end in React and TypeScript
• Build the client-side data and streaming layer
• Extend NodeZero's tenant isolation model to agents that take write actions
• Develop core product features in ETL and GraphQL
• Build the ETL pipelines for researcher datasets
• Instrument everything including distributed tracing and cost accounting

Required qualifications

• Bachelor's Degree in Computer Science, Computer Engineering or related field
• 7+ yrs professional software engineering experience using modern object-oriented or functional languages (Python, Go, Scala, C++, TypeScript, etc)
• Proven experience delivering backend APIs, especially GraphQL, and consuming them from a modern web stack
• Production experience with React, TypeScript, and modern CSS layout
• Experience building applications on cloud computing platforms such as AWS, Azure, GCP, using container technologies such as Docker and Kubernetes
• Expert proficiency in SQL
• Demonstrated experience designing and operating distributed systems in production: asynchronous workflows, queues, retries, idempotency, and partial failure
• A track record of shipping and operating production services, including on-call ownership

Nice to have

• Experience building agentic or LLM-backed systems in production
• Experience with a durable execution (such as Temporal) or workflow engine or having built equivalent checkpointing yourself
• Experience building multi-tenant platforms with hard isolation requirements, workload identity, and short-lived credential brokering
• Experience integrating a long tail of third-party APIs behind a normalized abstraction
• Familiarity with security control planes and their APIs — EDR (CrowdStrike, SentinelOne, Microsoft Defender), firewalls, SIEM, cloud IAM
• Experience with database architectures including relational (PostgreSQL) and graph (Neo4j), and experience building GraphQL backends
• Experience with client-side data and streaming patterns — React Query or Apollo, GraphQL subscriptions, WebSockets
• Experience building operator-facing or admin interfaces
• Experience with observability tooling (Datadog, Prometheus, Grafana) and distributed tracing
• Awareness of prompt injection and untrusted-input handling

Benefits

• equity package in the form of stock options
• health, vision & dental insurance for you and your family
• flexible vacation policy
• generous parental leave

About the company

Horizon3 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.