Principal Software Engineer, Agentic Data Platform

Horizon
3.ai http://Horizon
3.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.

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 25

Mbps consumer grade broadband connection.

The Principal Engineer for Database Platform is the technical anchor of Node Zero's data infrastructure. This is an individual contributor role with no direct reports — your influence is through technical leadership, architecture ownership, and raising the engineering bar across the team. You own the most consequential database architecture decisions, define the standards that govern how Node Zero stores, queries, and migrates data at scale, and ensure the data layer can support Node Zero's growth — more customers, larger environments, more pentest data — without requiring proportional operational effort.

This is a deeply hands-on role: you will write code, author design documents, and set the technical direction that every engineer on the Database Platform team builds toward.

Node Zero's data layer is not simple. We store millions of discovered assets, graph-structured attack paths, time-series vulnerability data, and audit-critical pentest results — across a multi-tenant architecture where correctness and data isolation are non-negotiable. You will be the person who makes the hardest data architecture calls and ensures the team has the technical foundations to build reliably on.

• Technical Strategy:
  Define and drive the technical roadmap for the Database Platform in partnership with the Senior Engineering Manager and the broader Pentest Platform organization.
• Architecture Leadership:
  Own the most complex database architecture decisions — schema design, partitioning strategies, migration patterns, and scalability approaches. Produce design documents that become the shared technical model for the team.
• PostgreSQL Excellence:
  Be Node Zero's definitive expert on PostgreSQL at scale — query optimization, indexing, partitioning, replication, and connection pooling. Set the standards the team follows and catch the problems others miss.
• Graph & Multi-model Data:
  Architect and guide the evolution of Node Zero's graph-based asset model — the data structure that represents how discovered hosts, services, credentials, and vulnerabilities relate to each other across pentests.
• Schema Governance:
  Own schema design review processes. Ensure every migration is safe, reversible, and zero-downtime. Build the tooling and culture that treats schema changes with the same rigor as production code changes.
• Mentorship & Bar Raising:
  Mentor P5 and P4 engineers through code review, design review, and pairing. Be the person on the team that raises everyone else's ceiling.
• Cross-functional Influence:
  Partner with Data Ingestion, Asset Inventory, API Platform, and Security Research to define data contracts, query performance standards, and architectural guardrails that span the full data pipeline.

• Deep, production-proven PostgreSQL expertise: query planner internals, advanced indexing (partial, expression,…