Staff Software Engineer, Database Platform at horizon3ai · LumiJobs

Responsibilities

The Staff Engineer on the Data Platform team is the technical anchor for database architecture and reliability across Horizon3. NodeZero runs thousands of pentests generating enormous volumes of structured data — vulnerability findings, asset graphs, scan histories, time-series telemetry, and customer configurations. Every team at Horizon3 depends on the data stores this team builds and operates. You will set the technical direction for how Horizon3 designs, provisions, scales, and operates its database systems — from PostgreSQL and graph databases to time-series stores.
This is a hands-on staff-level role. You will write production code, produce architecture designs, drive critical performance and reliability decisions, and mentor engineers through the craft of database engineering. The team is building from a small but strong foundation — your job is to raise the technical bar dramatically as the data volumes and query complexity grow. This role reports to the Data Platform Engineering Manager.
Database Architecture: Set the technical direction for Horizon3's database systems — schema design philosophy, data modeling standards, indexing strategies, and query contract design across teams
Performance Engineering: Own query performance across the platform — identify slow queries, produce execution plan analyses, implement fixes, and design the observability systems that catch regressions early
Reliability & Operations: Own the reliability engineering for all data stores — replication, failover, backup validation, capacity planning, and database incident response
Migration Engineering: Design and own the migration framework that makes schema evolution safe in production — zero-downtime migrations, reversible changes, and migration testing standards
Cross-team Enablement: Serve as the database expert for application engineering teams — review their schemas, query patterns, and ORM usage; set the access patterns that prevent problems from reaching production
Mentorship: Mentor P4 engineers through design review, code review, and deep technical pairing; be the person the team turns to when they hit a hard database problem
What You'll Bring
Database Engineering
8+ years of professional software engineering experience with deep specialization in database systems and data infrastructure
Expert-level PostgreSQL proficiency — you have tuned complex production query plans, managed replication topology, and debugged the hardest vacuum and locking issues

Staff Software Engineer, Database Platform

Responsibilities

Qualification

Preferred

Benefits

Company

horizon3ai

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