Principal Engineer, AI Cloud Software

Responsibilities

• Own the software architecture behind it: service boundaries and the control-plane model. Set a target architecture two to three years ahead and plan the steps from today's system to it.
• Design the control plane to keep each region serving when another fails, protect it under load with per-tenant rate limits and fair queuing, and remove the limits that would block growth in tenants, resource types, sites, and request volume.
• Lead design reviews for significant changes across the teams, sign off architecture decision records, and settle technical disputes escalated by engineers. Decide at pace with incomplete information, write down the assumptions, and revisit a decision when the evidence changes.

Build and evolve

• Write production code for the hardest parts of the API and the control plane.
• Keep the console, SDKs, CLI, and Terraform provider consistent with the API, built from a single contract. Ship each capability as a supported feature, not a one-off for a single customer.
• Set SLOs and error budgets for the API and control plane and use the budget to decide when reliability work comes first.
• Lead the technical response to major incidents in the API and control plane and make sure every post-mortem ends with a fix that stops it happening again.
• Design usage records accurate enough to bill from and for customers to verify, with quotas and audit logs that customers can query through the API and export.
• Design every service to survive rolling node replacement without customer impact, and keep dependencies and images patched within policy.
• Keep Firmus' SOC 2 Type 2 and ISO 27001 controls passing at every new site.
• Grow engineers through mentorship, design review, and code review. Hiring and performance review sit with the Engineering Manager.
• Set the software engineering standards other teams build to, covering API design, testing, code review, and service templates. Each team’s principal still owns the architecture of their domain.
• Set how the team uses AI to build software effectively and securely, with review gates and automated architecture checks that keep AI-generated code within the agreed design.
• Shape the technical roadmap with product and deliver API and architecture work ahead of the features that depend on it.
• Agree ownership in writing at each boundary

ROLE SUMMARY

Firmus Technologies is seeking a Principal Engineer, AI Cloud Software to own the Firmus AI Cloud API and the control plane behind it. Customers, partner platforms, and AI agents use our API to provision and run GPU compute, and our console, SDKs, CLI, and Terraform provider are all built on it. You will set the technical direction for all of it. Everything you design must work across sites and scale to hundreds of thousands of GPUs in gigawatt-scale AI factories.

Architecture and decisions

Own the overall design of the public API: the resource model, contracts, versioning, and the compatibility promise customers and partner platforms build against. Set one contract style, one identity model, and one versioning policy that every domain team follows.

Expose the full lifecycle of compute, virtual networking, storage, and Kubernetes resources through the API, on top of the infrastructure, network and storage controllers' other teams own. Give every resource a stable identifier, track multi-step requests to completion, and offer break-fix actions such as reboot, reset, and maintenance notices.

Build identity and tenancy into the API: organisations and projects, federated sign-on with MFA, automated user provisioning, group-based roles, and service accounts.

Give customers, partner platforms, Firmus operations teams, and AI agents acting for a customer safe access through the same API, with scoped credentials, approval for destructive actions, and a full audit trail.

Reliability, security, and cost

Own cost at the design level and raise any design change that alters what customers consume.

Technical leadership

• Own the technical interviews and assessments for software engineers and hold every candidate to that bar.
• Partnership and communication