Principal Software Engineer, Agentic Data Platform

Get to Know Us

Horizon3.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. Our flagship product, the NodeZero™ platform, delivers production-safe autonomous pentests and other key assessment operations that scale across the largest internal, external, cloud, and hybrid cloud environments. NodeZero has been adopted by organizations of all sizes, from small educational institutions to government agencies and Global 100 enterprises. It is used by IT Ops/SecOps teams, consulting pentesters, and MSSPs and MSPs.

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 25Mbps consumer grade broadband connection.

What You'll Do

The Principal Engineer for Database Platform is the technical anchor of NodeZero'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 NodeZero stores, queries, and migrates data at scale, and ensure the data layer can support NodeZero'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.

NodeZero'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 NodeZero'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 NodeZero'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.

What You'll Bring

Technical Depth

Deep, production-proven PostgreSQL expertise: query planner internals, advanced indexing (partial, expression, GiST/GIN), partitioning strategies, logical replication, vacuuming at scale, and connection pool tuning.

Experience architecting multi-tenant databases at scale: row-level security, tenant isolation, schema-per-tenant vs. shared-schema tradeoffs.

Experience with schema migration at scale in production systems: zero-downtime migrations, backwards-compatible schema evolution, and migration tooling (Flyway, golang-migrate, or equivalent).

Familiarity with graph data models and graph databases (Neo4j, AWS Neptune) or graph-like query patterns in relational systems (recursive CTEs, ltree, adjacency list).

Proficient in Go or Python — able to write production application code, not just SQL.

Architecture & Design

Demonstrated track record of defining database architecture at scale — from design doc to production — across multiple companies or teams.

Strong opinions on data architecture tradeoffs: normalization vs. denormalization, consistency vs. availability, OLTP vs. OLAP workload separation, and schema-first vs. schema-last design.

Able to reason about long-horizon schema design: what does this schema look like in two years, at 10× the current data volume, with three new feature teams writing to it?

Able to communicate complex database decisions clearly in writing — for design docs, ADRs, and cross-team reviews — so engineers without deep DB expertise can understand and apply the reasoning.

Leadership Without Authority

Proven ability to drive database standards across multiple teams without direct reporting authority — including teams that are not the Database Platform team.

Experience establishing database engineering culture: schema review norms, migration safety standards, and query performance review processes.

Track record of growing engineers through code review, pair programming, and architectural mentorship — especially engineers who are strong in application code but earlier in their database expertise.

Nice to Haves

Background in cybersecurity data: vulnerability databases, network scan schemas, or attack surface management data models.

Experience with time-series databases (TimescaleDB, InfluxDB) in addition to relational.

Familiarity with data platform compliance requirements: SOC 2 Type II, FedRAMP data handling, or GDPR/CCPA.

Experience with analytical query patterns or BI/reporting workloads on operational data.

Contributions to open-source database tooling or PostgreSQL ecosystem projects.

Travel Required

We are a fully remote company, and this job may require up to 5% of travel to be successful.

Compensation and Values

At Horizon3, we believe that our people are our greatest asset, and our compensation philosophy reflects this core value. We are committed to fostering an environment where all employees feel valued, respected, and rewarded for their contributions. Our compensation structure is designed to be fair, competitive, and transparent, ensuring that every team member is recognized and compensated equitably across roles, levels, and locations.

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