Principal/Senior Engineer Software - Agentic Endpoint Security(Cortex)

We are looking for an experienced and highly capable Principal/Senior Software Engineer to join the Koi team. This role is focused on building and scaling a complex, high-impact product that operates across large-scale enterprise environments. As a Principal Engineer, you will take ownership of major parts of the system and work across the full stack, including backend services, data pipelines, frontend applications, and endpoint/agent code. You will play a key role in shaping the architecture of Koi as it grows, ensuring the system remains scalable, reliable, and easy to evolve.
Key Responsibilities
Design and build scalable, high-performance systems across the full Koi stack
Own architecture and technical direction for critical components
Work across backend, data, frontend, and agent code
Tackle complex challenges related to scale, reliability, and performance
Drive best practices in system design, testing, and observability
Collaborate closely with product, security, and customer-facing teams
Identify and resolve bottlenecks and architectural limitations
Mentor other engineers and raise the overall technical bar of the team.