Senior Software Engineer

F5; Cardiff; Hybrid; GBP 70,000 - 100,000; Full time

Job summary

F5 in Cardiff is seeking a Senior AI Software Engineer with strong C#/.NET and Azure expertise to design and deliver LLM-powered applications and AI agents for a major technology consultancy serving a public-sector client. The role emphasizes practical AI delivery over research, with opportunities to demonstrate your builds and outcomes.

The position offers mostly remote work with occasional Cardiff presence and requires UK SC clearance eligibility.

Qualifications

• Strong C#/.NET and Microsoft Azure
• Hands-on experience building LLM applications or AI agents
• Exposure to Azure OpenAI, RAG, APIs or agent orchestration
• Ability to explain and demonstrate your technical work
• SC clearance eligibility required

Responsibilities

• Design and develop AI-enabled software using C#/.NET and Azure
• Build and deploy LLM-powered applications or AI agents
• Integrate Azure OpenAI, APIs and RAG for orchestration
• Demonstrate technical work and results to stakeholders

Skills

C#

.NET

Azure

LLM

AI agents

Tools

Azure OpenAI

APIs

RAG

Job description

Senior AI Software Engineer | .NET & Azure | £70,000 - £100,000

Are you a strongC#/.NET and Azure engineer who has recently started building AI agents or applications using LLMs?

I'm working on an exciting opportunity with a major technology consultancy, supporting a public-sector client in Cardiff.

They're looking for an experienced software engineer who can combine solid development skills with practical, demonstrable AI experience.

You don't need to be an AI research expert. If you've been tasked with building agents or LLM-powered applications in your current role and can talk confidently about what you've built, this could be a great next step.

Key experience:

• Strong C#/.NET and Microsoft Azure
• Hands-on experience building LLM applications or AI agents
• Exposure to Azure OpenAI, RAG, APIs or agent orchestration
• Ability to explain and demonstrate your technical work

Location: Cardiff

Working pattern: Primarily remote, with around 2-3 days per month in Cardiff

Salary: £70,000-£100,000, depending on experience

SC clearance eligibility required

Interview: One technical Teams interview