Principal Software Engineer: Cloud Platform

📋 Job Overview

As a Principal Software Engineer at Radiant, you’ll be a hands-on technical leader, driving the design and development of our most critical systems, including our GPU orchestration layer, inference-serving infrastructure, and core platform APIs. You’ll set the standard for engineering excellence across the team, working closely with other principal engineers to align on strategy and drive technical leadership. You’ll partner with peers in infrastructure and machine learning to deliver high-performance AI systems, and mentor engineers across multiple squads. While you won’t have direct reports, you’ll play a pivotal role in shaping engineering direction, design decisions, and cross-team collaboration.

🏢 About Radiant

What sets us apart is our blend of modern technology, competitive benefits, and an open, welcoming work culture that enables our people to thrive. Here are just some of the great things you can expect from us: 25 days of annual leave, a culture that emphasises results over hierarchy, process & ego, open communication, regular feedback, learning time, health & wellbeing benefits, cycle to work scheme, gympass subscription, participation in the company shares program, enhanced parental pay & leave, and diversity, equality, inclusion and belonging.

🎯 The Role

You’ll be a hands-on technical leader, driving the design and development of our most critical systems, including our GPU orchestration layer, inference-serving infrastructure, and core platform APIs. You’ll set the standard for engineering excellence across the team, working closely with other principal engineers to align on strategy and drive technical leadership. You’ll partner with peers in infrastructure and machine learning to deliver high-performance AI systems, and mentor engineers across multiple squads. While you won’t have direct reports, you’ll play a pivotal role in shaping engineering direction, design decisions, and cross-team collaboration.

✅ Key Responsibilities

• Design and develop core services for the Radiant AI Cloud
• Architect and build core backend services in Go that power AI infrastructure, networking, inference orchestration, and model lifecycle management
• Lead engineering design efforts across the backend domain - architecture reviews, and system evolution strategies
• Collaborate closely with platform and infrastructure to deliver reliable, secure, production-grade services
• Drive technical standards and mentorship, upholding code quality, observability, and maintainability across teams
• Proactively identify and resolve architectural bottlenecks, performance issues, or scaling challenges

📌 Required Qualifications

• Proven expertise in Golang and cloud-native backend development
• Deep experience designing and deploying distributed systems and APIs (gRPC, REST) in production environments
• Strong knowledge of Kubernetes internals, with deep understanding of primitives, deployments and reconciliation loops.
• Experience with PostgreSQL or equivalent high-performance data stores
• Experience with CI/CD workflows, observability, security and automation best practices
• Demonstrated ability to lead technically: mentor others, drive architectural thinking, and influence across teams
• A bias for action, accountability, and leading by example

⭐ Desirable Experience

• Experience with AI/ML infrastructure tooling (e.g. vLLM, KServe, Ray, Triton)
• Familiarity with Python, especially ML libraries and model interfaces
• Familiarity with GPU scheduling, inference pipelines, or resource-constrained workload orchestration
• Exposure to GPU orchestration frameworks or building services for model training/inference
• Understanding of multi-tenant systems, isolation strategies, and secure infrastructure for AI workloads

🎁 Benefits

• 25 days of annual leave
• A culture that emphasises 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
• Diversity, Equality, Inclusion and Belonging

🛂 Visa & Eligibility

We are an equal opportunity employer and we strive to reduce unconscious bias throughout our hiring process. All applicants will be considered for employment without attention to ethnicity, religion, sexual orientation, gender identity, family or parental status, national origin, veteran, neurodiversity status or disability status. To ensure our recruitment processes provide an equal opportunity for all applicants to succeed, we encourage you to let us know if there are any adjustments that we can make.