Principal Software Engineer, Database Platform

📋 Job Overview

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. 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.

🏢 About Horizon3

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.

🎯 The Role

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.

✅ Key Responsibilities

• Define and drive the technical roadmap for the Database Platform in partnership with the Senior Engineering Manager and the broader Pentest Platform organization.
• 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.
• 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.
• 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.
• 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.
• Mentor P5 and P4 engineers through code review, design review, and pairing. Be the person on the team that raises everyone else's ceiling.
• 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.

📌 Required Qualifications

• 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.
• 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.
• 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