Remote Senior Full-Stack Engineer — Autonomous Defense Platform

horizon3ai; United States; Hybrid; USD 120,000 - 170,000; Full time

Benefits offered by this job

Stock options

Health, vision, and dental coverage

Flexible vacation

Parental leave

Job summary

horizon3ai is building the platform that runs autonomous defensive agents across customer environments. You will own backend systems and operator-facing interfaces, ensuring durable, observable, and safe agent workflows at scale.

Focus areas include execution, orchestration, integrations, data processing, and a production-first mindset. You will work with AI researchers while maintaining reliable systems across many environments.

Qualifications

• Must have strong backend engineering experience with distributed systems.
• Ability to deliver frontend features as part of end-to-end products.
• Capable of building reliable systems across many customer environments.
• Understand how to make actions controlled, observable, and auditable.
• Experience working with AI researchers while supporting production systems.

Responsibilities

• Develop a runtime for long-running agent workflows with checkpoints, resumable steps, timeouts, and cancellation.
• Create a versioned tool registry with schema checks and server-side authorization.
• Build connectors to security systems (endpoint protection, firewalls, identity, SIEM, cloud access).
• Implement safeguards: simulation, impact assessment, approvals, staged rollout, rollback, auditable records.
• Build operator interfaces in React and TypeScript with live WebSocket updates.
• Strengthen tenant isolation with execution boundaries, egress controls, quotas, and data leakage protection.

Skills

Backend engineering

Distributed systems

Frontend features

Reliability across environments

Observability & auditable

Collaboration with AI researchers

Tools

React

TypeScript

WebSockets

Job description

horizon3ai is building the platform that runs autonomous defensive agents across customer environments. You will own backend systems and operator-facing interfaces, ensuring durable, observable, and safe agent workflows at scale.

Focus areas include execution, orchestration, integrations, data processing, and a production-first mindset. You will work with AI researchers while maintaining reliable systems across many environments.