Senior Backend Software Engineer - Backend Systems

Radiant; Greater London; On-site; GBP 110,000 - 150,000; Full time

Benefits offered by this job

25 days leave

Private medical insurance

Cycle to Work

Gympass

Employee share plan

Enhanced parental pay & leave

Job summary

Radiant in London seeks a Senior Software Engineer to lead hands-on development of our GPU orchestration layer, inference infrastructure, and core APIs. You’ll set engineering standards and mentor multiple squads, collaborating with ML and infra teams to deliver high-performance AI systems.

The role emphasizes ownership, secure, scalable services, and high-quality code. You'll influence architectural decisions and drive cross-team initiatives in a fast-paced environment.

Qualifications

• Production-grade backend services in Go required.
• Experience deploying distributed systems in production.
• Strong Kubernetes and API design experience.
• Security and observability best practices.
• Ownership mindset and collaboration across squads.

Responsibilities

• Design and build backend services in Go powering AI infra.
• Implement secure, reliable APIs (gRPC/REST).
• Develop Kubernetes Operators to manage resources.
• Contribute to architectural discussions and system evolution.
• Collaborate with platform and infra teams for scalable services.
• Maintain code quality, observability, and maintainability through reviews.

Skills

Golang

Distributed systems

gRPC/REST APIs

Kubernetes internals

CI/CD workflows

Observability

Security best practices

Ownership

Tools

Kubernetes

CI/CD pipelines

Observability tooling

Job description

About the Role:

As a Senior 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.

What You’ll Do:

• Design and build backend services in Go that power AI infrastructure, networking, inference orchestration, and model lifecycle management
• Implement secure, reliable APIs (gRPC/REST) and backend systems
• Design and develop Kubernetes Operators to manage compute and networking resources
• Contribute to architectural discussions, providing input on design reviews and system evolution
• Collaborate closely with platform and infrastructure teams to deliver production-grade, secure, and scalable services
• Maintain high standards for code quality, observability, and maintainability through reviews and best practices

What You Bring:

• Proven experience developing production systems in Golang
• Hands-on experience designing and deploying distributed systems and APIs (gRPC, REST) in production environments
• Solid understanding of Kubernetes internals (Scheduler, CNI, Operators, CSI, CAPI)
• Familiarity with CI/CD workflows, observability tooling, security, and automation best practices
• Collaborate across teams, contribute to architectural and development best practices
• A bias for ownership, accountability, and delivering high-quality software

Preferred Skills (Nice to Have):

• Infrastructure and networking knowledge
• Experience with Authentication, Authorization, RBAC and security best practices.
• Nvidia hardware and software (GPU, Cumulus, NVLink)

Qualities we look for:

• Set the standard: Every single day, you spot opportunities to constructively shake things up.
• Inspire the change: There's no blueprint for the future. You’ll embrace challenges and change.
• You’re real and you’re true to yourself: We cherish and celebrate diversity so you’ll feel right at home whoever you are and whoever you’re talking to, you treat everyone the same.

Why should you join us?

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: 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

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.