Principal Platform Engineer

📋 Job Overview

As a Principal Platform Engineer, you will help set the technical direction for the platform one of our engineering teams builds on: the infrastructure, tooling, and automation that let us run GPU clusters, Kubernetes, and our managed services reliably at scale. You'll partner closely with software engineers, SRE, Infra Ops, and the other platform engineers across Radiant. This is a hands-on technical leadership role focused on making the platform reliable, secure, and easy to build on, through architecture, code, and the standards other teams build on.

🏢 About Radiant

Radiant is redefining how AI infrastructure is built. We design and operate AI-native cloud platforms engineered for sovereignty, performance, and scale. Our infrastructure powers GPU-native workloads, multi-tenant control planes, and high-performance AI systems designed for the most demanding environments. We are not building a generic cloud. We are building purpose-built AI infrastructure — from powered land, to compute, to software. As we scale, we're building this organization from the ground up. We're looking for people who'd rather build the playbook than inherit one — who are comfortable doing the work themselves as well as directing others, and who can adapt as fast as our strategy does. This is a startup model: attitude and adaptability matter more to us than years of experience or the size of the team you've previously managed.

🎯 The Role

You will help set the technical direction for the platform one of our engineering teams builds on: the infrastructure, tooling, and automation that let us run GPU clusters, Kubernetes, and our managed services reliably at scale. You'll partner closely with software engineers, SRE, Infra Ops, and the other platform engineers across Radiant.

✅ Key Responsibilities

• Set the platform architecture and roadmap for your team, and lead its design and implementation.
• Lead infrastructure-as-code, automation, and deployment at scale.
• Make environments reproducible, secure, and fast to change.
• Own the reliability and operability of the platform, with SRE and Infra Ops.
• Define standards for CI/CD, observability, and configuration across teams.
• Raise the engineering bar through mentoring, design and code review, and technical standards.

📌 Required Qualifications

• Extensive experience in platform, infrastructure, or SRE engineering at scale.
• A track record of technical leadership at staff or principal level, including setting direction across multiple teams and delivering complex, high-stakes systems.
• Strong hands-on engineering skills in Go, Python, or similar.
• Deep technical expertise across:
• Kubernetes and containers in production, including operators
• Infrastructure-as-code and configuration management (e.g. Terraform, Ansible)
• CI/CD, release engineering, and GitOps
• Linux, networking, and cloud or bare-metal infrastructure
• Excellent written and verbal communication, including clear design documents and explaining complex trade-offs to technical and non-technical audiences.

⭐ Desirable Experience

• Experience with GPU, HPC, or bare-metal platforms is a strong plus.

🎁 Benefits

• 25 days of annual leave
• A culture that emphasizes results over hierarchy, process & ego: we place great emphasis on the quality, ingenuity and creativity of work.
• Open communication, regular feedback: we value smooth collaboration, direct and actionable feedback, and believe that leading with empathy and a growth mindset makes us better together.
• Learning Time: we all have dedicated learning time to focus on new skills, projects or interests that lay outside of your day-to-day job.
• Health & Wellbeing: we want everyone to feel healthy and happy, so we offer private medical insurance via Bupa.
• Cycle to Work Scheme: we're committed to building a sustainable business, so we encourage cycling to work.
• Gympass subscription to a variety of gyms and wellbeing apps
• Participation in the company shares program
• Enhanced parental pay & leave

🛂 Visa & Eligibility

Our process: Talent screen → Hiring Manager → Technical interview (two Principal Engineers) → Whiteboard → Session Final.