Principal Engineer, Platform

Firmus Technologies Firmus Technologies is a global leader pioneering the development and operation of efficient AI infrastructure across Asia Pacific. Founded in Australia in 2019, our mission is to create the most efficient AI infrastructure by combining cutting-edge technology with a steadfast commitment to sustainability. At Firmus, we are unique in our approach. We design, build, and operate a new class of digital infrastructure – the AI Factory. Through our model-to-grid technology approach, we have pushed the boundaries of multi-generational liquid cooling systems, energy management, AI software orchestration, and construction. For our customers, this approach allows us to make every watt count and deliver low-cost AI tokens globally. Firmus AI Cloud Our large-scale GPU cloud platform, Firmus AI Cloud, is purpose-built to deliver energy-efficient AI compute at scale to customers. It empowers developers, enterprises, educational institutions, and government users to train and deploy AI models with unmatched efficiency and cost savings. With an ever-growing suite of services and applications, we are committed to delivering a cloud experience that is market-leading, proprietary, and built to scale. ROLE SUMMARY Firmus Technologies is seeking a Principal Engineer, Platform to own the platform Firmus engineers build and release on, in public cloud and in our own data centres. Self-service and security come first: through one golden path, an engineer should be able to create a service, get an environment, and ship to production securely with minimal support. Everything you design must work across sites and scale to hundreds of thousands of GPUs in gigawatt-scale AI factories. KEY RESPONSIBILITIES Architecture and Decisions • Own the architecture of the engineering platform and its multi-site management plane, in public cloud and on premises. Set a target architecture two to three years ahead and plan the steps from today's system to it. • Design the platform around a repeatable scaling unit. Capacity grows in identical units, a failure stays inside one unit or site, and each site meets a defined standard before it carries the platform. • Decide how internal Kubernetes and hypervisor clusters are built, networked, upgraded, and recovered. Keep Kubernetes conformant and close to upstream releases, with upgrades that need no downtime. New sites come up from code and the site deployment kit, and recovery is tested regularly. • Decide how services are packaged, released, and promoted with progressive rollout, and how a failed release is rolled back and contained across sites. • 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 • Own engineer self-service with an API-first design. The CLI, automation, and any developer portal all use the same platform API. Treat every ticket to the platform team as a gap in self-service and close the most common ones first. • Keep a service catalogue in code, with an owner for every service and scorecards that show each team where its services stand against the golden path, production-readiness, and security standards. • Provide multi-cluster deployment for internal teams and the customer product: one pipeline to every region and data centre, the customer product isolated from internal workloads, and sites that keep running when the orchestrator is unreachable. • Let AI agents work on the delivery path under the same controls as engineers, with their own identity, least privilege, sandboxing, and a person approving every production change. Reliability, security, and cost • Set SLOs and error budgets for the platform and use the budget to decide when reliability work comes first. • Lead the technical response to major incidents in the platform and make sure every post-mortem ends with a fix that stops it happening again. • Set the standard every change meets before it goes live: code review, acceptance tests, builds traceable from source to deploy, and the application security team's controls in every pipeline by default. • Provide secrets, certificates, and single sign-on as platform services, built to the security team's identity and secrets standard, with mutual TLS between services and credentials issued from code, short-lived, and rotated automatically. • Build continuous compliance for SOC 2 Type 2 and ISO 27001 into the platform, with controls written as policy in code, evidence collected automatically, and drift detected and corrected. • Automate patching without disruption and land urgent and embargoed security fixes within defined timelines. Nodes are replaced site by site from rebuilt images, within each service's disruption limits and with automatic rollback. • Own cost at the design level, including cloud spend, with one shared path for every team and site. Technical leadership • Grow engineers through mentorship, design review, and code review. Hiring and performance review sit with the Engineering Manager. • 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. • Own the technical interviews and assessments for platform engineers and hold every candidate to that bar. Partnership and communication • Shape the platform roadmap with product, infrastructure, network, and site-delivery leaders, and have the platform ready before each new region or data centre goes live. • Agree ownership in writing at each boundary with infrastructure, network, security, software, data and observability, and settle disagreements directly. • Represent the platform team in customer and auditor reviews of security, reliability, and compliance. SKILLS AND EXPERIENCE • Bachelor's degree in computer science or a related technical field, or equivalent practical experience. • 10+ years in platform, infrastructure, or software engineering, including at least 3 years at principal level or equivalent, setting the technical direction that multiple teams delivered against. You are still hands-on and intend to stay that way. • Has owned a golden path other engineers used to ship: infrastructure as code (such as Terraform or OpenTofu), CI/CD, and GitOps (such as Argo CD or Flux), with progressive rollout, rollback, artifact signing and provenance, and security gates in the pipeline. • Has run a platform as a product, with self-service through templates and a platform API or CLI that teams adopted, measured by adoption and delivery performance rather than uptime alone. • Has built, upgraded, and recovered Kubernetes on self-managed servers, including on virtualised infrastructure, as well as in a public cloud such as AWS, across more than one site. • Deep, practical knowledge of Kubernetes internals: the API server and etcd, scheduling, networking (such as Cilium, with mutual TLS), storage, and admission control. • Strong in Go or Python, with services, controllers, or tools other teams consume, not only infrastructure code. • Has built security into a platform: secrets management (such as Vault or OpenBao), certificate automation, short-lived credentials, and fleet patching with no visible impact on services, under SOC 2 Type 2, ISO 27001, or an equivalent control set. • Has run a reliability programme other engineers followed: SLOs and error budgets, change control, and incident reviews that changed the system. • Clear written and verbal communication in English, able to explain problems, decisions, and trade-offs to engineers, executives, and customers. • Willing to join the on-call rotation for the services you own and to travel overseas occasionally. Location & Reporting • Location: we are open to offer capable candidates to be based in either Australia or Singapore • Report to: Senior Manager, Platform Engineering Employment Basis Full-time Diversity At Firmus, we are committed to building a diverse and inclusive workplace. We encourage applications from candidates of all backgrounds who are passionate about creating a more sustainable future through innovative engineering solutions. Join us in our mission to revolutionize the AI industry through sustainable practices and cutting-edge engineering. Apply now to be part of shaping the future of sustainable AI infrastructure.